[MoE Refactor][16/N] Apply Refactor to NVFP4 (#31692)

Signed-off-by: Robert Shaw <robshaw@redhat.com>
Signed-off-by: Robert Shaw <114415538+robertgshaw2-redhat@users.noreply.github.com>
Co-authored-by: Robert Shaw <robshaw@redhat.com>
Co-authored-by: Michael Goin <mgoin64@gmail.com>
Co-authored-by: Pavani Majety <pmajety@nvidia.com>

benchmarks/kernels/benchmark_cutlass_moe_nvfp4.py

@@ -11,14 +11,20 @@ import nvtx
 import torch
 import torch.utils.benchmark as benchmark
 
+import vllm.model_executor.layers.fused_moe.modular_kernel as mk
 from vllm import _custom_ops as ops
 from vllm.config import ParallelConfig, VllmConfig, set_current_vllm_config
 from vllm.model_executor.layers.fused_moe.config import (
     fp8_w8a8_moe_quant_config,
     nvfp4_moe_quant_config,
 )
-from vllm.model_executor.layers.fused_moe.cutlass_moe import cutlass_moe_fp4
+from vllm.model_executor.layers.fused_moe.cutlass_moe import (
+    CutlassExpertsFp4,
+)
 from vllm.model_executor.layers.fused_moe.fused_moe import fused_experts, fused_topk
+from vllm.model_executor.layers.fused_moe.prepare_finalize import (
+    MoEPrepareAndFinalizeNoEP,
+)
 from vllm.scalar_type import scalar_types
 from vllm.utils.argparse_utils import FlexibleArgumentParser
 from vllm.v1.worker.workspace import init_workspace_manager
@@ -188,19 +194,24 @@ def bench_run(
             g1_alphas=w1_gs,
             g2_alphas=w2_gs,
         )
+
+        kernel = mk.FusedMoEModularKernel(
+            MoEPrepareAndFinalizeNoEP(defer_input_quant=True),
+            CutlassExpertsFp4(
+                out_dtype=dtype,
+                max_experts_per_worker=e,
+                quant_config=quant_config,
+            ),
+        )
+
         for _ in range(num_repeats):
             with nvtx.annotate("cutlass_moe_fp4", color="green"):
-                cutlass_moe_fp4(
-                    a=a,
-                    w1_fp4=w1_fp4,
-                    w2_fp4=w2_fp4,
+                kernel(
+                    hidden_states=a,
+                    w1=w1_fp4,
+                    w2=w2_fp4,
                     topk_weights=topk_weights,
                     topk_ids=topk_ids,
-                    m=m,
-                    n=n,
-                    k=k,
-                    e=num_experts,
-                    quant_config=quant_config,
                 )
 
     def run_cutlass_from_graph(
@@ -230,20 +241,24 @@ def bench_run(
             g2_alphas=w2_gs,
         )
 
+        kernel = mk.FusedMoEModularKernel(
+            MoEPrepareAndFinalizeNoEP(defer_input_quant=True),
+            CutlassExpertsFp4(
+                out_dtype=dtype,
+                max_experts_per_worker=e,
+                quant_config=quant_config,
+            ),
+        )
+
         with set_current_vllm_config(
             VllmConfig(parallel_config=ParallelConfig(pipeline_parallel_size=1))
         ):
-            return cutlass_moe_fp4(
-                a=a,
-                w1_fp4=w1_fp4,
-                w2_fp4=w2_fp4,
+            return kernel(
+                hidden_states=a,
+                w1=w1_fp4,
+                w2=w2_fp4,
                 topk_weights=topk_weights,
                 topk_ids=topk_ids,
-                m=m,
-                n=n,
-                k=k,
-                e=num_experts,
-                quant_config=quant_config,
             )
 
     def run_triton_from_graph(

docs/design/moe_kernel_features.md

@@ -86,7 +86,7 @@ To be used with a particular `FusedMoEPrepareAndFinalize` subclass, MoE kernels
 | triton | standard | all<sup>1</sup> | G,A,T | silu, gelu,</br>swigluoai,</br>silu_no_mul,</br>gelu_no_mul | Y | Y | [`fused_experts`][vllm.model_executor.layers.fused_moe.fused_moe.fused_experts],</br>[`TritonExperts`][vllm.model_executor.layers.fused_moe.fused_moe.TritonExperts] |
 | triton (batched) | batched | all<sup>1</sup> | G,A,T | silu, gelu | <sup>6</sup> | Y | [`BatchedTritonExperts`][vllm.model_executor.layers.fused_moe.fused_batched_moe.BatchedTritonExperts] |
 | deep gemm | standard,</br>batched | fp8 | G(128),A,T | silu, gelu | <sup>6</sup> | Y | [`deep_gemm_moe_fp8`][vllm.model_executor.layers.fused_moe.deep_gemm_moe.deep_gemm_moe_fp8],</br>[`DeepGemmExperts`][vllm.model_executor.layers.fused_moe.deep_gemm_moe.DeepGemmExperts],</br>[`BatchedDeepGemmExperts`][vllm.model_executor.layers.fused_moe.batched_deep_gemm_moe.BatchedDeepGemmExperts] |
-| cutlass_fp4 | standard,</br>batched | nvfp4 | A,T | silu | Y | Y | [`cutlass_moe_fp4`][vllm.model_executor.layers.fused_moe.cutlass_moe.cutlass_moe_fp4],</br>[`CutlassExpertsFp4`][vllm.model_executor.layers.fused_moe.cutlass_moe.CutlassExpertsFp4] |
+| cutlass_fp4 | standard,</br>batched | nvfp4 | A,T | silu | Y | Y | [`CutlassExpertsFp4`][vllm.model_executor.layers.fused_moe.cutlass_moe.CutlassExpertsFp4] |
 | cutlass_fp8 | standard,</br>batched | fp8 | A,T | silu, gelu | Y | Y | [`CutlassExpertsFp8`][vllm.model_executor.layers.fused_moe.cutlass_moe.CutlassExpertsFp8],</br>[`CutlasBatchedExpertsFp8`][vllm.model_executor.layers.fused_moe.cutlass_moe.CutlassBatchedExpertsFp8] |
 | flashinfer | standard | nvfp4,</br>fp8 | T | <sup>5</sup> | N | Y | [`flashinfer_cutlass_moe_fp4`][vllm.model_executor.layers.fused_moe.flashinfer_cutlass_moe.flashinfer_cutlass_moe_fp4],</br>[`FlashInferExperts`][vllm.model_executor.layers.fused_moe.flashinfer_cutlass_moe.FlashInferExperts] |
 | gpt oss triton | standard | N/A | N/A | <sup>5</sup> | Y | Y | [`triton_kernel_fused_experts`][vllm.model_executor.layers.fused_moe.gpt_oss_triton_kernels_moe.triton_kernel_fused_experts],</br>[`OAITritonExperts`][vllm.model_executor.layers.fused_moe.gpt_oss_triton_kernels_moe.OAITritonExperts] |

tests/kernels/moe/test_nvfp4_moe.py

@@ -3,6 +3,7 @@
 import pytest
 import torch
 
+import vllm.model_executor.layers.fused_moe.modular_kernel as mk
 from tests.kernels.moe.utils import make_test_weights
 from tests.kernels.quantization.nvfp4_utils import (
     FLOAT4_E2M1_MAX,
@@ -13,8 +14,13 @@ from tests.kernels.utils import torch_moe
 from vllm import _custom_ops as ops
 from vllm.config import ParallelConfig, VllmConfig, set_current_vllm_config
 from vllm.model_executor.layers.fused_moe.config import nvfp4_moe_quant_config
-from vllm.model_executor.layers.fused_moe.cutlass_moe import cutlass_moe_fp4
+from vllm.model_executor.layers.fused_moe.cutlass_moe import (
+    CutlassExpertsFp4,
+)
 from vllm.model_executor.layers.fused_moe.fused_moe import fused_topk
+from vllm.model_executor.layers.fused_moe.prepare_finalize import (
+    MoEPrepareAndFinalizeNoEP,
+)
 from vllm.platforms import current_platform
 from vllm.utils.torch_utils import set_random_seed
 
@@ -83,17 +89,21 @@ def test_cutlass_fp4_moe_no_graph(
             w2_scale=w2_blockscale,
         )
 
-        cutlass_output = cutlass_moe_fp4(
-            a=a,
-            w1_fp4=w1_q,
-            w2_fp4=w2_q,
+        kernel = mk.FusedMoEModularKernel(
+            MoEPrepareAndFinalizeNoEP(defer_input_quant=True),
+            CutlassExpertsFp4(
+                out_dtype=dtype,
+                max_experts_per_worker=e,
+                quant_config=quant_config,
+            ),
+        )
+
+        cutlass_output = kernel(
+            hidden_states=a,
+            w1=w1_q,
+            w2=w2_q,
             topk_weights=topk_weights,
             topk_ids=topk_ids,
-            quant_config=quant_config,
-            m=m,
-            n=n,
-            k=k,
-            e=e,
         )
 
         # Reference check:

vllm/model_executor/layers/fused_moe/__init__.py

@@ -72,7 +72,6 @@ if HAS_TRITON:
         CutlassBatchedExpertsFp8,
         CutlassExpertsFp8,
         CutlassExpertsW4A8Fp8,
-        cutlass_moe_fp4,
         cutlass_moe_w4a8_fp8,
     )
     from vllm.model_executor.layers.fused_moe.deep_gemm_moe import DeepGemmExperts
@@ -95,7 +94,6 @@ if HAS_TRITON:
         "fused_experts",
         "get_config_file_name",
         "GroupedTopk",
-        "cutlass_moe_fp4",
         "cutlass_moe_w4a8_fp8",
         "CutlassExpertsFp8",
         "CutlassBatchedExpertsFp8",

vllm/model_executor/layers/fused_moe/config.py

@@ -336,6 +336,10 @@ class FusedMoEQuantConfig:
     def use_int4_w4a16(self) -> bool:
         return self._a1.dtype is None and self._w1.dtype == "int4"
 
+    @property
+    def use_nvfp4_w4a16(self) -> bool:
+        return self._a1.dtype is None and self._w1.dtype == "nvfp4"
+
     @property
     def ocp_mx_scheme(self) -> str | None:
         if not hasattr(self, "_ocp_mx_scheme"):
@@ -690,6 +694,25 @@ def nvfp4_moe_quant_config(
     )
 
 
+def nvfp4_w4a16_moe_quant_config(
+    g1_alphas: torch.Tensor,
+    g2_alphas: torch.Tensor,
+    w1_scale: torch.Tensor,
+    w2_scale: torch.Tensor,
+) -> FusedMoEQuantConfig:
+    """
+    Construct a quant config for 16-but activations and nvp4 weights.
+    """
+    return FusedMoEQuantConfig.make(
+        quant_dtype=None,
+        w1_scale=w1_scale,
+        w2_scale=w2_scale,
+        g1_alphas=g1_alphas,
+        g2_alphas=g2_alphas,
+        weight_dtype="nvfp4",
+    )
+
+
 def int4_w4a16_moe_quant_config(
     w1_scale: torch.Tensor,
     w2_scale: torch.Tensor,

vllm/model_executor/layers/fused_moe/cutlass_moe.py

@@ -706,68 +706,6 @@ class CutlassExpertsFp4(mk.FusedMoEPermuteExpertsUnpermute):
         )
 
 
-def cutlass_moe_fp4(
-    a: torch.Tensor,
-    w1_fp4: torch.Tensor,
-    w2_fp4: torch.Tensor,
-    topk_weights: torch.Tensor,
-    topk_ids: torch.Tensor,
-    quant_config: FusedMoEQuantConfig,
-    m: int,
-    n: int,
-    k: int,
-    e: int,
-    expert_map: torch.Tensor | None = None,
-    apply_router_weight_on_input: bool = False,
-) -> torch.Tensor:
-    assert expert_map is None, (
-        "Expert Parallelism / expert_map "
-        "is currently not supported for "
-        "ModelOptNvFp4FusedMoE's cutlass_moe_fp4."
-    )
-
-    # TODO(bnell): this feels a bit hacky
-    # NVFP4 requires two levels of quantization, which involves
-    # computing some scaling factors dynamically. This makes it
-    # incompatible with the typical prepare -> MoE -> finalize
-    # pipeline. Move the quantization logic into the MoE body.
-    quant_config = FusedMoEQuantConfig.make(
-        quant_dtype=None,  # skip quantization in prepare/finalize
-        per_act_token_quant=quant_config.per_act_token_quant,
-        per_out_ch_quant=quant_config.per_out_ch_quant,
-        block_shape=quant_config.block_shape,
-        g1_alphas=quant_config.g1_alphas,
-        g2_alphas=quant_config.g2_alphas,
-        a1_gscale=quant_config.a1_gscale,
-        a2_gscale=quant_config.a2_gscale,
-        w1_scale=quant_config.w1_scale,
-        w2_scale=quant_config.w2_scale,
-    )
-
-    fn = mk.FusedMoEModularKernel(
-        MoEPrepareAndFinalizeNoEP(),
-        CutlassExpertsFp4(
-            max_experts_per_worker=e,
-            out_dtype=a.dtype,
-            quant_config=quant_config,
-            use_batched_format=False,
-        ),
-    )
-
-    return fn(
-        hidden_states=a,
-        w1=w1_fp4,
-        w2=w2_fp4,
-        topk_weights=topk_weights,
-        topk_ids=topk_ids,
-        inplace=False,
-        activation="silu",
-        global_num_experts=e,
-        expert_map=None,
-        apply_router_weight_on_input=apply_router_weight_on_input,
-    )
-
-
 # W4A8
 def run_cutlass_moe_w4a8_fp8(
     output: torch.Tensor,

vllm/model_executor/layers/fused_moe/flashinfer_cutedsl_moe.py

@@ -335,42 +335,3 @@ def flashinfer_cutedsl_moe_masked(
         alpha_dtype=get_cute_dtype(w2_alpha),
     )  # in logical [m, k, l]
     out = out.permute(2, 0, 1)
-
-
-def flashinfer_cutedsl_moe_fp4(
-    hidden_states: torch.Tensor,
-    w1: torch.Tensor,
-    w2: torch.Tensor,
-    topk_weights: torch.Tensor,
-    topk_ids: torch.Tensor,
-    quant_config: FusedMoEQuantConfig,
-    inplace: bool = False,
-    activation: str = "silu",
-    global_num_experts: int = -1,
-    expert_map: torch.Tensor | None = None,
-    apply_router_weight_on_input: bool = False,
-) -> torch.Tensor:
-    from vllm.model_executor.layers.fused_moe.flashinfer_cutlass_prepare_finalize import (  # noqa: E501
-        create_flashinfer_prepare_finalize,
-    )
-
-    fused_experts = mk.FusedMoEModularKernel(
-        create_flashinfer_prepare_finalize(use_dp=False),  # could be swapped later
-        FlashInferCuteDSLExperts(
-            out_dtype=hidden_states.dtype,
-            quant_config=quant_config,
-        ),
-    )
-
-    return fused_experts(
-        hidden_states=hidden_states,
-        w1=w1,
-        w2=w2,
-        topk_weights=topk_weights,
-        topk_ids=topk_ids,
-        inplace=inplace,
-        activation=activation,
-        global_num_experts=global_num_experts,
-        expert_map=expert_map,
-        apply_router_weight_on_input=apply_router_weight_on_input,
-    )

vllm/model_executor/layers/fused_moe/flashinfer_cutlass_prepare_finalize.py

@@ -355,21 +355,17 @@ def create_flashinfer_prepare_finalize(
     use_deepseek_fp8_block_scale: bool = False,
 ) -> FlashInferCutlassMoEPrepareAndFinalize | MoEPrepareAndFinalizeNoEP:
     """Factory function to create the appropriate FlashInfer implementation."""
-    # TODO(rob): migrate non-DP cases to MoEPrepareAndFinalizeNoEP
-    # once we complete the FP8 refactor.
-    if use_nvfp4:
-        if enable_alltoallv:
-            return FlashInferAllToAllMoEPrepareAndFinalize(use_dp)
-        else:
-            return FlashInferAllGatherMoEPrepareAndFinalize(use_dp)
 
-    # FP8 DP path currently supported via AllGather.
     if use_dp:
+        if enable_alltoallv:
+            assert use_nvfp4
+            return FlashInferAllToAllMoEPrepareAndFinalize(use_dp)
         return FlashInferAllGatherMoEPrepareAndFinalize(
             use_dp=True,
             use_deepseek_fp8_block_scale=use_deepseek_fp8_block_scale,
         )
     else:
-        # NOTE(rob): CUTLASS FP8 block quant executes the input
-        # quantzation and grouped gemm in a single kernel.
-        return MoEPrepareAndFinalizeNoEP(defer_input_quant=use_deepseek_fp8_block_scale)
+        # CUTLASS FP8 BLOCK and CUTLASS NVFP4 apply input quantization
+        # in a single call with the MoE experts kernel.
+        defer_input_quant = use_deepseek_fp8_block_scale or use_nvfp4
+        return MoEPrepareAndFinalizeNoEP(defer_input_quant=defer_input_quant)

vllm/model_executor/layers/fused_moe/fused_marlin_moe.py

@@ -540,9 +540,10 @@ class MarlinExpertsBase(mk.FusedMoEPermuteExpertsUnpermute):
         # TODO (varun) : Enable activation quantization
         assert (
             quant_config.use_mxfp4_w4a16
+            or quant_config.use_nvfp4_w4a16
             or quant_config.use_int4_w4a16
             or quant_config.use_fp8_w8a16
-        ), "Supports only mxfp4_w4a16, int4_w4a16 or fp8_w8a16"
+        ), "Supports only {mxfp,nvfp,int}4_w4a16 or fp8_w8a16"
         self.w13_g_idx = w13_g_idx
         self.w2_g_idx = w2_g_idx
         self.w13_g_idx_sort_indices = w13_g_idx_sort_indices
@@ -555,7 +556,7 @@ class MarlinExpertsBase(mk.FusedMoEPermuteExpertsUnpermute):
         # uint4b8 will be set for int4 weight and float4_e2m1f will be used for mxfp4
         if self.quant_config.use_int4_w4a16:
             return scalar_types.uint4b8.id
-        elif self.quant_config.use_mxfp4_w4a16:
+        elif self.quant_config.use_mxfp4_w4a16 or self.quant_config.use_nvfp4_w4a16:
             return scalar_types.float4_e2m1f.id
         elif (
             self.quant_config.use_fp8_w8a16
@@ -692,6 +693,8 @@ class MarlinExperts(MarlinExpertsBase):
             gating_output=None,
             topk_weights=topk_weights,
             topk_ids=topk_ids,
+            global_scale1=self.g1_alphas,
+            global_scale2=self.g2_alphas,
             quant_type_id=self.quant_type_id,
             apply_router_weight_on_input=apply_router_weight_on_input,
             global_num_experts=global_num_experts,

vllm/model_executor/layers/fused_moe/layer.py

@@ -38,9 +38,6 @@ from vllm.model_executor.layers.fused_moe.routing_simulator import RoutingSimula
 from vllm.model_executor.layers.quantization.base_config import (
     QuantizationConfig,
 )
-from vllm.model_executor.layers.quantization.utils.flashinfer_utils import (
-    is_flashinfer_supporting_global_sf,
-)
 from vllm.platforms import current_platform
 from vllm.utils.flashinfer import has_flashinfer_trtllm_fused_moe
 from vllm.utils.math_utils import cdiv, round_up
@@ -1125,14 +1122,9 @@ class FusedMoE(CustomOp):
         global_expert_id = expert_id
         expert_id = self._map_global_expert_id_to_local_expert_id(global_expert_id)
 
-        allow_flashinfer = getattr(self.quant_method, "allow_flashinfer", False)
-        moe_backend = getattr(self.quant_method, "flashinfer_moe_backend", None)
-
         use_global_sf = (
-            allow_flashinfer
-            and is_flashinfer_supporting_global_sf(moe_backend)
+            getattr(self.quant_method, "use_global_sf", False)
             and "input_scale" in weight_name
-            and quant_method_name == "ModelOptNvFp4FusedMoE"
         )
 
         if expert_id == -1 and not use_global_sf:

vllm/model_executor/layers/fused_moe/oracle/nvfp4.py

+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+from enum import Enum
+
+import torch
+
+import vllm.envs as envs
+import vllm.model_executor.layers.fused_moe.modular_kernel as mk
+from vllm.logger import init_logger
+from vllm.model_executor.layers.fused_moe.config import (
+    FusedMoEConfig,
+    FusedMoEQuantConfig,
+    nvfp4_moe_quant_config,
+    nvfp4_w4a16_moe_quant_config,
+)
+from vllm.model_executor.layers.fused_moe.cutlass_moe import (
+    CutlassExpertsFp4,
+)
+from vllm.model_executor.layers.fused_moe.flashinfer_cutlass_moe import (
+    FlashInferExperts,
+)
+from vllm.model_executor.layers.fused_moe.fused_marlin_moe import (
+    MarlinExperts,
+)
+from vllm.model_executor.layers.fused_moe.prepare_finalize import (
+    MoEPrepareAndFinalizeNoEP,
+)
+from vllm.model_executor.layers.quantization.utils.flashinfer_fp4_moe import (
+    is_flashinfer_fp4_cutedsl_moe_available,
+    is_flashinfer_fp4_cutlass_moe_available,
+    prepare_nvfp4_moe_layer_for_fi_or_cutlass,
+)
+from vllm.model_executor.layers.quantization.utils.flashinfer_utils import (
+    FlashinferMoeBackend,
+    get_flashinfer_moe_backend,
+)
+from vllm.model_executor.layers.quantization.utils.marlin_utils_fp4 import (
+    is_fp4_marlin_supported,
+    prepare_nvfp4_moe_layer_for_marlin,
+)
+from vllm.model_executor.layers.quantization.utils.quant_utils import (
+    cutlass_fp4_supported,
+)
+
+logger = init_logger(__name__)
+
+
+class NvFp4MoeBackend(Enum):
+    FLASHINFER_CUTLASS = "FlashInfer CUTLASS"
+    FLASHINFER_TRTLLM = "FlashInfer TRTLLM"
+    FLASHINFER_CUTEDSL = "FlashInfer CUTEDSL"
+    VLLM_CUTLASS = "vLLM CUTASS"
+    MARLIN = "vLLM MARLIN"
+
+
+FLASHINFER_NVFP4_MOE_BACKENDS = [
+    NvFp4MoeBackend.FLASHINFER_CUTLASS,
+    NvFp4MoeBackend.FLASHINFER_TRTLLM,
+    NvFp4MoeBackend.FLASHINFER_CUTEDSL,
+]
+
+fi_2_vllm_backend_map: dict[FlashinferMoeBackend, NvFp4MoeBackend] = {
+    FlashinferMoeBackend.CUTLASS: NvFp4MoeBackend.FLASHINFER_CUTLASS,
+    FlashinferMoeBackend.TENSORRT_LLM: NvFp4MoeBackend.FLASHINFER_TRTLLM,
+    FlashinferMoeBackend.CUTEDSL: NvFp4MoeBackend.FLASHINFER_CUTEDSL,
+}
+
+
+def is_global_sf_supported_for_nvfp4_backend(backend: NvFp4MoeBackend) -> bool:
+    # Checks whether `backend` supports quantizing with scaling factors
+    # of all experts in Expert Parallel Mode when all experts are not
+    # on the same rank.
+
+    return backend in [
+        NvFp4MoeBackend.FLASHINFER_CUTLASS,
+        NvFp4MoeBackend.FLASHINFER_TRTLLM,
+    ]
+
+
+def select_nvfp4_moe_backend() -> NvFp4MoeBackend:
+    def _make_log_backend(backend: NvFp4MoeBackend):
+        return f"Using {backend.value} backend for NvFp4 MoE"
+
+    if cutlass_fp4_supported() and not envs.VLLM_TEST_FORCE_FP8_MARLIN:
+        allow_flashinfer = (
+            is_flashinfer_fp4_cutlass_moe_available()
+            or is_flashinfer_fp4_cutedsl_moe_available()
+        )
+        if allow_flashinfer and envs.VLLM_USE_FLASHINFER_MOE_FP4:
+            backend = fi_2_vllm_backend_map[get_flashinfer_moe_backend()]
+        else:
+            backend = NvFp4MoeBackend.VLLM_CUTLASS
+    elif is_fp4_marlin_supported():
+        backend = NvFp4MoeBackend.MARLIN
+    else:
+        raise ValueError("No NvFp4 kernel backend available for NvFp4 MoE.")
+
+    # Log warning if FI backend requested but not available.
+    if (
+        backend not in FLASHINFER_NVFP4_MOE_BACKENDS
+        and envs.VLLM_USE_FLASHINFER_MOE_FP4
+    ):
+        logger.warning_once(
+            "Requested FlashInfer backend for NvFp4 MoE, but it's not available. "
+            "Falling back to %s for NvFp4 MoE",
+            backend.value,
+            scope="local",
+        )
+    else:
+        logger.info_once(_make_log_backend(backend), scope="local")
+    return backend
+
+
+def convert_to_nvfp4_moe_kernel_format(
+    nvfp4_backend: NvFp4MoeBackend,
+    layer: torch.nn.Module,
+    w13: torch.Tensor,
+    w13_scale: torch.Tensor,
+    w13_scale_2: torch.Tensor,
+    a13_scale: torch.Tensor | None,
+    w2: torch.Tensor,
+    w2_scale: torch.Tensor,
+    w2_scale_2: torch.Tensor,
+    a2_scale: torch.Tensor | None,
+    is_act_and_mul: bool,
+) -> tuple[
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+]:
+    if (
+        nvfp4_backend in FLASHINFER_NVFP4_MOE_BACKENDS
+        or nvfp4_backend == NvFp4MoeBackend.VLLM_CUTLASS
+    ):
+        (
+            w13,
+            w13_scale,
+            w13_scale_2,
+            a13_scale,
+            w2,
+            w2_scale,
+            w2_scale_2,
+            a2_scale,
+        ) = prepare_nvfp4_moe_layer_for_fi_or_cutlass(
+            backend=nvfp4_backend,
+            layer=layer,
+            w13=w13,
+            w13_scale=w13_scale,
+            w13_scale_2=w13_scale_2,
+            a13_scale=a13_scale,
+            w2=w2,
+            w2_scale=w2_scale,
+            w2_scale_2=w2_scale_2,
+            a2_scale=a2_scale,
+            is_act_and_mul=is_act_and_mul,
+        )
+    elif nvfp4_backend == NvFp4MoeBackend.MARLIN:
+        a13_scale = None
+        a2_scale = None
+        (
+            w13,
+            w13_scale,
+            w13_scale_2,
+            w2,
+            w2_scale,
+            w2_scale_2,
+        ) = prepare_nvfp4_moe_layer_for_marlin(
+            layer=layer,
+            w13=w13,
+            w13_scale=w13_scale,
+            w13_scale_2=w13_scale_2,
+            w2=w2,
+            w2_scale=w2_scale,
+            w2_scale_2=w2_scale_2,
+        )
+    else:
+        raise ValueError(f"Unknown NvFp4 backend for MoE: {nvfp4_backend}")
+
+    return (
+        w13,
+        w13_scale,
+        w13_scale_2,
+        a13_scale,
+        w2,
+        w2_scale,
+        w2_scale_2,
+        a2_scale,
+    )
+
+
+def make_nvfp4_moe_quant_config(
+    backend: NvFp4MoeBackend,
+    w13_scale: torch.Tensor,
+    w2_scale: torch.Tensor,
+    w13_scale_2: torch.Tensor,
+    w2_scale_2: torch.Tensor,
+    a13_scale: torch.Tensor,
+    a2_scale: torch.Tensor,
+) -> FusedMoEQuantConfig | None:
+    UNSUPPORTED = [NvFp4MoeBackend.FLASHINFER_TRTLLM]
+    if backend in UNSUPPORTED:
+        return None
+
+    elif backend == NvFp4MoeBackend.MARLIN:
+        return nvfp4_w4a16_moe_quant_config(
+            g1_alphas=w13_scale_2,
+            g2_alphas=w2_scale_2,
+            w1_scale=w13_scale,
+            w2_scale=w2_scale,
+        )
+
+    g1_alphas = a13_scale * w13_scale_2
+    g2_alphas = a2_scale * w2_scale_2
+    return nvfp4_moe_quant_config(
+        g1_alphas=g1_alphas,
+        g2_alphas=g2_alphas,
+        a1_gscale=(1.0 / a13_scale),
+        a2_gscale=(1.0 / a2_scale),
+        w1_scale=w13_scale,
+        w2_scale=w2_scale,
+    )
+
+
+def make_nvfp4_moe_kernel(
+    backend: NvFp4MoeBackend,
+    quant_config: FusedMoEQuantConfig,
+    moe_config: FusedMoEConfig,
+) -> mk.FusedMoEModularKernel | None:
+    assert moe_config.dp_size == 1
+
+    UNSUPPORTED_BACKENDS = [
+        # TRTLLM does not use the modular kernl abstraction.
+        NvFp4MoeBackend.FLASHINFER_TRTLLM,
+        # CUTEDSL is used with BATCHED (masked) format only.
+        # TODO: add here once we support dp/ep via the oracle.
+        NvFp4MoeBackend.FLASHINFER_CUTEDSL,
+    ]
+
+    if backend in UNSUPPORTED_BACKENDS:
+        return None
+
+    elif backend == NvFp4MoeBackend.FLASHINFER_CUTLASS:
+        return mk.FusedMoEModularKernel(
+            MoEPrepareAndFinalizeNoEP(defer_input_quant=True),
+            FlashInferExperts(
+                out_dtype=moe_config.in_dtype,
+                quant_config=quant_config,
+                ep_rank=moe_config.ep_rank,
+                ep_size=moe_config.ep_size,
+                tp_rank=moe_config.tp_rank,
+                tp_size=moe_config.tp_size,
+                use_dp=False,
+                use_deepseek_fp8_block_scale=False,
+            ),
+        )
+
+    elif backend == NvFp4MoeBackend.VLLM_CUTLASS:
+        return mk.FusedMoEModularKernel(
+            MoEPrepareAndFinalizeNoEP(defer_input_quant=True),
+            CutlassExpertsFp4(
+                out_dtype=moe_config.in_dtype,
+                # TODO(rob): see what impact this has on expert map?
+                max_experts_per_worker=moe_config.num_experts,
+                quant_config=quant_config,
+            ),
+        )
+
+    elif backend == NvFp4MoeBackend.MARLIN:
+        return mk.FusedMoEModularKernel(
+            MoEPrepareAndFinalizeNoEP(),
+            MarlinExperts(quant_config=quant_config),
+        )
+
+    else:
+        raise ValueError(f"Unknown NvFp4 MoE backend: {backend}")

vllm/model_executor/layers/quantization/compressed_tensors/compressed_tensors_moe.py

@@ -11,7 +11,6 @@ from compressed_tensors.quantization import (
     QuantizationArgs,
     QuantizationStrategy,
 )
-from torch.nn.parameter import Parameter
 
 import vllm.model_executor.layers.fused_moe.modular_kernel as mk
 from vllm import _custom_ops as ops
@@ -34,12 +33,8 @@ from vllm.model_executor.layers.fused_moe.config import (
     int4_w4afp8_moe_quant_config,
     int8_w8a8_moe_quant_config,
     int8_w8a16_moe_quant_config,
-    nvfp4_moe_quant_config,
 )
 from vllm.model_executor.layers.fused_moe.cpu_fused_moe import select_experts
-from vllm.model_executor.layers.fused_moe.flashinfer_cutlass_moe import (
-    is_valid_flashinfer_cutlass_fused_moe,
-)
 from vllm.model_executor.layers.fused_moe.fused_marlin_moe import (
     BatchedMarlinExperts,
     MarlinExperts,
@@ -51,6 +46,15 @@ from vllm.model_executor.layers.fused_moe.oracle.fp8 import (
     make_fp8_moe_kernel,
     select_fp8_moe_backend,
 )
+from vllm.model_executor.layers.fused_moe.oracle.nvfp4 import (
+    FLASHINFER_NVFP4_MOE_BACKENDS,
+    NvFp4MoeBackend,
+    convert_to_nvfp4_moe_kernel_format,
+    is_global_sf_supported_for_nvfp4_backend,
+    make_nvfp4_moe_kernel,
+    make_nvfp4_moe_quant_config,
+    select_nvfp4_moe_backend,
+)
 from vllm.model_executor.layers.quantization.compressed_tensors.schemes.compressed_tensors_wNa16 import (  # noqa
     WNA16_SUPPORTED_BITS,
     WNA16_SUPPORTED_TYPES_MAP,
@@ -58,14 +62,9 @@ from vllm.model_executor.layers.quantization.compressed_tensors.schemes.compress
 from vllm.model_executor.layers.quantization.utils.flashinfer_fp4_moe import (
     build_flashinfer_fp4_cutlass_moe_prepare_finalize,
     flashinfer_trtllm_fp4_moe,
-    prepare_static_weights_for_trtllm_fp4_moe,
-    reorder_w1w3_to_w3w1,
+    flashinfer_trtllm_fp4_routed_moe,
     select_nvfp4_gemm_impl,
 )
-from vllm.model_executor.layers.quantization.utils.flashinfer_utils import (
-    FlashinferMoeBackend,
-    get_flashinfer_moe_backend,
-)
 from vllm.model_executor.layers.quantization.utils.fp8_utils import (
     process_fp8_input_tensor_strategy_moe,
     process_fp8_weight_tensor_strategy_moe,
@@ -77,20 +76,15 @@ from vllm.model_executor.layers.quantization.utils.marlin_utils import (
     marlin_make_workspace_new,
     marlin_moe_permute_scales,
 )
-from vllm.model_executor.layers.quantization.utils.marlin_utils_fp4 import (
-    prepare_moe_fp4_layer_for_marlin,
-)
 from vllm.model_executor.layers.quantization.utils.quant_utils import (
     convert_bf16_scales_to_fp8,
     convert_packed_uint4b8_to_signed_int4_inplace,
-    swizzle_blockscale,
 )
 from vllm.model_executor.layers.quantization.utils.w8a8_utils import (
     normalize_e4m3fn_to_e4m3fnuz,
 )
 from vllm.model_executor.utils import replace_parameter, set_weight_attrs
 from vllm.platforms import CpuArchEnum, current_platform
-from vllm.scalar_type import scalar_types
 
 logger = init_logger(__name__)
 
@@ -218,31 +212,19 @@ class CompressedTensorsMoEMethod(FusedMoEMethodBase):
 
 class CompressedTensorsW4A4Nvfp4MoEMethod(CompressedTensorsMoEMethod):
     def __init__(self, moe: FusedMoEConfig, layer_name: str | None = None):
-        from vllm.model_executor.layers.quantization.utils.nvfp4_moe_support import (  # noqa: E501
-            detect_nvfp4_moe_support,
-        )
+        if not moe.is_act_and_mul:
+            raise ValueError(
+                "CompressedTensorsW4A4Nvfp4MoEMethod does not yet "
+                "support non gated MoE models."
+            )
 
         super().__init__(moe)
-        _nvfp4 = detect_nvfp4_moe_support(self.__class__.__name__)
-        self.cutlass_nvfp4_supported = _nvfp4.cutlass_supported
-        self.allow_flashinfer = _nvfp4.allow_flashinfer
-        self.use_marlin = _nvfp4.use_marlin
         self.group_size = 16
-        self.layer_name = layer_name
-        self.marlin_input_dtype = (
-            get_marlin_input_dtype(layer_name) if self.use_marlin else None
-        )
-        self.flashinfer_moe_backend = None
-        if self.allow_flashinfer:
-            self.flashinfer_moe_backend = get_flashinfer_moe_backend()
-            logger.info_once(
-                f"Using FlashInfer {self.flashinfer_moe_backend.value} kernels"
-                " for CompressedTensorsW4A4Nvfp4MoEMethod."
-            )
-        elif self.use_marlin:
-            logger.info_once("Using Marlin for CompressedTensorsW4A4Nvfp4MoEMethod.")
-        else:
-            logger.info_once("Using Cutlass for CompressedTensorsW4A4Nvfp4MoEMethod.")
+        self.nvfp4_backend = select_nvfp4_moe_backend()
+        self.use_global_sf = is_global_sf_supported_for_nvfp4_backend(
+            self.nvfp4_backend
+        )
+        self.kernel: mk.FusedMoEModularKernel | None = None
 
     def create_weights(
         self,
@@ -355,7 +337,13 @@ class CompressedTensorsW4A4Nvfp4MoEMethod(CompressedTensorsMoEMethod):
         set_weight_attrs(w2_input_scale, extra_weight_attrs)
 
     def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
-        # From packed to weight
+        """
+        Convert NVFP4 MoE weights into kernel format and setup the kernel.
+        """
+        # NOTE(rob): wN_weight_packed -> wN_weight is because ModularKernelMethod
+        # requires this naming convention. However, the name change breaks
+        # reloading because the state dict no longer matches disk. Once we
+        # remove MKM, we should revert this change to ensure compatibility.
         layer.w13_weight = torch.nn.Parameter(
             layer.w13_weight_packed.data, requires_grad=False
         )
@@ -366,144 +354,79 @@ class CompressedTensorsW4A4Nvfp4MoEMethod(CompressedTensorsMoEMethod):
         )
         delattr(layer, "w2_weight_packed")
 
-        # reorder GEMM1 weights and block scales for FlashInfer CUTLASS kernel.
-        if self.allow_flashinfer:
-            w, s = reorder_w1w3_to_w3w1(
-                layer.w13_weight.data, layer.w13_weight_scale.data, dim=-2
-            )
-            layer.w13_weight = torch.nn.Parameter(w, requires_grad=False)
-            layer.w13_weight_scale = torch.nn.Parameter(s, requires_grad=False)
-
-        if not torch.allclose(
+        # Use a single gscale for w13.
+        if self.moe.is_act_and_mul and not torch.allclose(
             layer.w13_weight_global_scale[:, 0], layer.w13_weight_global_scale[:, 1]
         ):
             logger.warning_once(
                 "w1_weight_global_scale must match w3_weight_global_scale. "
-                "Accuracy may be affected."
-            )
-
-        # Take inverse of global scale saved to disk
-        layer.w13_weight_scale_2 = torch.nn.Parameter(
-            1 / layer.w13_weight_global_scale[:, 0], requires_grad=False
-        )
-
-        layer.w2_weight_scale_2 = torch.nn.Parameter(
-            1 / layer.w2_weight_global_scale.data, requires_grad=False
-        )
-
-        if self.use_marlin:
-            prepare_moe_fp4_layer_for_marlin(layer, input_dtype=self.marlin_input_dtype)
-            return
-        # w13
-        if (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
-            w13_input_global_scale = (
-                layer.w13_input_global_scale.min()
-                .to(torch.float32)
-                .expand(layer.num_experts)
-            )
-        else:
-            w13_input_global_scale = layer.w13_input_global_scale.min(dim=1).values.to(
-                torch.float32
-            )
-        layer.g1_alphas = torch.nn.Parameter(
-            ((1 / w13_input_global_scale) * layer.w13_weight_scale_2),
-            requires_grad=False,
-        )
-
-        layer.w13_input_scale_quant = torch.nn.Parameter(
-            (w13_input_global_scale), requires_grad=False
-        )
-
-        # w2
-        if (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
-            w2_input_global_scale = (
-                layer.w2_input_global_scale.min()
-                .to(torch.float32)
-                .expand(layer.num_experts)
-            )
-        else:
-            w2_input_global_scale = layer.w2_input_global_scale
-
-        layer.g2_alphas = torch.nn.Parameter(
-            ((1 / w2_input_global_scale) * layer.w2_weight_scale_2).to(torch.float32),
-            requires_grad=False,
-        )
-
-        layer.w2_input_scale_quant = torch.nn.Parameter(
-            (w2_input_global_scale), requires_grad=False
+                "Accuracy may be affected.",
+            )
+        w13_weight_global_scale = layer.w13_weight_global_scale[:, 0].contiguous()
+
+        # Shuffle weights into the NvFp4 kernel format.
+        (
+            w13,
+            w13_scale,
+            w13_scale_2,
+            a13_scale,
+            w2,
+            w2_scale,
+            w2_scale_2,
+            a2_scale,
+        ) = convert_to_nvfp4_moe_kernel_format(
+            nvfp4_backend=self.nvfp4_backend,
+            layer=layer,
+            w13=layer.w13_weight,
+            w13_scale=layer.w13_weight_scale,
+            w13_scale_2=(1.0 / w13_weight_global_scale),
+            a13_scale=(1.0 / layer.w13_input_global_scale),
+            w2=layer.w2_weight,
+            w2_scale=layer.w2_weight_scale,
+            w2_scale_2=(1.0 / layer.w2_weight_global_scale),
+            a2_scale=(1.0 / layer.w2_input_global_scale),
+            is_act_and_mul=self.moe.is_act_and_mul,
         )
 
-        # TensorRT-LLM specific processing
-        if (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
-            # Prepare static weights for TRT-LLM kernel
-            # alternate: prepare_static_weight_layouts_for_trtllm_moe
-            (
-                gemm1_weights_fp4_shuffled,
-                gemm1_scales_fp4_shuffled,
-                gemm2_weights_fp4_shuffled,
-                gemm2_scales_fp4_shuffled,
-            ) = prepare_static_weights_for_trtllm_fp4_moe(
-                layer.w13_weight,
-                layer.w2_weight,
-                layer.w13_weight_scale,
-                layer.w2_weight_scale,
-                layer.w2_weight.size(-2),  # hidden_size
-                layer.w13_weight.size(-2) // 2,  # intermediate_size
-                layer.w13_weight.size(0),  # num_experts
-            )
-            logger.debug_once("Finished shuffling weights for TRT-LLM MOE")
-
-            layer.w13_weight = Parameter(
-                gemm1_weights_fp4_shuffled, requires_grad=False
-            )
-            layer.w2_weight = Parameter(gemm2_weights_fp4_shuffled, requires_grad=False)
-            layer.w13_weight_scale = Parameter(
-                gemm1_scales_fp4_shuffled, requires_grad=False
-            )
-            layer.w2_weight_scale = Parameter(
-                gemm2_scales_fp4_shuffled, requires_grad=False
-            )
-
-            # Additional parameter needed for TRT-LLM
-            layer.g1_scale_c = Parameter(
-                (layer.w2_input_scale_quant * layer.g1_alphas).to(torch.float32),
-                requires_grad=False,
-            )
-        else:
-            # swizzle weight scales
-            layer.w13_weight_scale = torch.nn.Parameter(
-                swizzle_blockscale(layer.w13_weight_scale), requires_grad=False
-            )
+        replace_parameter(layer, "w13_weight", w13)
+        replace_parameter(layer, "w13_weight_scale", w13_scale)
+        replace_parameter(layer, "w2_weight", w2)
+        replace_parameter(layer, "w2_weight_scale", w2_scale)
+        layer.w13_weight_scale_2 = w13_scale_2
+        layer.w2_weight_scale_2 = w2_scale_2
+        layer.w13_input_scale = a13_scale
+        layer.w2_input_scale = a2_scale
 
-            layer.w2_weight_scale = torch.nn.Parameter(
-                swizzle_blockscale(layer.w2_weight_scale), requires_grad=False
+        # Initialize the kernel that will be called in apply().
+        self.moe_quant_config = self.get_fused_moe_quant_config(layer)
+        use_dp = self.moe.dp_size > 1
+        if self.moe_quant_config is not None and not use_dp:
+            self.kernel = make_nvfp4_moe_kernel(
+                backend=self.nvfp4_backend,
+                quant_config=self.moe_quant_config,
+                moe_config=self.moe,
             )
 
     def maybe_make_prepare_finalize(
         self,
         routing_tables: tuple[torch.Tensor, torch.Tensor, torch.Tensor] | None = None,
     ) -> mk.FusedMoEPrepareAndFinalize | None:
-        if self.use_marlin or (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
+        UNSUPPORTED = [NvFp4MoeBackend.MARLIN, NvFp4MoeBackend.FLASHINFER_TRTLLM]
+        if self.nvfp4_backend in UNSUPPORTED:
             return None
-        elif not self.allow_flashinfer:
+        elif self.nvfp4_backend == NvFp4MoeBackend.FLASHINFER_CUTLASS:
+            # TP case: avoid convert to ModularKernelMethod - to be refactored.
+            if self.moe.dp_size == 1:
+                return None
+            # For now, fp4 moe only works with the flashinfer dispatcher.
+            prepare_finalize = build_flashinfer_fp4_cutlass_moe_prepare_finalize(
+                self.moe
+            )
+            logger.debug_once("%s", prepare_finalize.__class__.__name__)
+            return prepare_finalize
+        else:
             return super().maybe_make_prepare_finalize(routing_tables)
 
-        prepare_finalize = build_flashinfer_fp4_cutlass_moe_prepare_finalize(self.moe)
-        logger.debug_once("%s", prepare_finalize.__class__.__name__)
-        return prepare_finalize
-
     def select_gemm_impl(
         self,
         prepare_finalize: mk.FusedMoEPrepareAndFinalize,
@@ -514,7 +437,7 @@ class CompressedTensorsW4A4Nvfp4MoEMethod(CompressedTensorsMoEMethod):
         experts = select_nvfp4_gemm_impl(
             self.moe,
             self.moe_quant_config,
-            allow_flashinfer=self.allow_flashinfer,
+            allow_flashinfer=(self.nvfp4_backend in FLASHINFER_NVFP4_MOE_BACKENDS),
         )
         logger.debug_once("Using %s", experts.__class__.__name__)
         return experts
@@ -522,19 +445,14 @@ class CompressedTensorsW4A4Nvfp4MoEMethod(CompressedTensorsMoEMethod):
     def get_fused_moe_quant_config(
         self, layer: torch.nn.Module
     ) -> FusedMoEQuantConfig | None:
-        if (
-            self.use_marlin
-            or self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
-            return None
-
-        return nvfp4_moe_quant_config(
-            g1_alphas=layer.g1_alphas,
-            g2_alphas=layer.g2_alphas,
-            a1_gscale=layer.w13_input_scale_quant,
-            a2_gscale=layer.w2_input_scale_quant,
-            w1_scale=layer.w13_weight_scale,
+        return make_nvfp4_moe_quant_config(
+            backend=self.nvfp4_backend,
+            w13_scale=layer.w13_weight_scale,
             w2_scale=layer.w2_weight_scale,
+            w13_scale_2=layer.w13_weight_scale_2,
+            w2_scale_2=layer.w2_weight_scale_2,
+            a13_scale=layer.w13_input_scale,
+            a2_scale=layer.w2_input_scale,
         )
 
     def apply(
@@ -546,14 +464,9 @@ class CompressedTensorsW4A4Nvfp4MoEMethod(CompressedTensorsMoEMethod):
         assert layer.activation == "silu", "Only SiLU activation is supported."
 
         if (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
+            self.nvfp4_backend == NvFp4MoeBackend.FLASHINFER_TRTLLM
+            and not layer.enable_eplb
         ):
-            if layer.enable_eplb:
-                raise NotImplementedError(
-                    "EPLB not supported for `CompressedTensorsW4A4MoEMethod` yet."
-                )
-
             return flashinfer_trtllm_fp4_moe(
                 layer=layer,
                 x=x,
@@ -566,79 +479,41 @@ class CompressedTensorsW4A4Nvfp4MoEMethod(CompressedTensorsMoEMethod):
                 e_score_correction_bias=layer.e_score_correction_bias,
             )
 
+        # Hidden_states in select_experts is only used to extract metadata
+        if isinstance(x, tuple):
+            x_routing, _ = x
+        else:
+            x_routing = x
         topk_weights, topk_ids = layer.select_experts(
-            hidden_states=x,
+            hidden_states=x_routing,
             router_logits=router_logits,
         )
 
-        if self.use_marlin:
-            return fused_marlin_moe(
+        # EPLB path
+        if self.nvfp4_backend == NvFp4MoeBackend.FLASHINFER_TRTLLM:
+            assert layer.enable_eplb
+            return flashinfer_trtllm_fp4_routed_moe(
+                layer=layer,
+                x=x,
+                topk_ids=topk_ids,
+                topk_weights=topk_weights,
+                top_k=layer.top_k,
+                global_num_experts=layer.global_num_experts,
+            )
+        else:
+            assert self.kernel is not None
+            return self.kernel(
                 x,
                 layer.w13_weight,
                 layer.w2_weight,
-                None,
-                None,
-                layer.w13_weight_scale,
-                layer.w2_weight_scale,
-                router_logits,
                 topk_weights,
                 topk_ids,
-                global_scale1=layer.w13_weight_scale_2,
-                global_scale2=layer.w2_weight_scale_2,
-                quant_type_id=scalar_types.float4_e2m1f.id,
-                apply_router_weight_on_input=layer.apply_router_weight_on_input,
-                global_num_experts=layer.global_num_experts,
-                expert_map=layer.expert_map,
-                input_dtype=self.marlin_input_dtype,
-                workspace=layer.workspace,
-            )
-
-        # FlashInfer fused experts path
-        elif self.allow_flashinfer:
-            from vllm.model_executor.layers.fused_moe.flashinfer_cutlass_moe import (  # noqa: E501
-                flashinfer_cutlass_moe_fp4,
-            )
-
-            assert is_valid_flashinfer_cutlass_fused_moe(
-                x, layer.w13_weight, layer.w2_weight
-            ), "Flashinfer CUTLASS Fused MoE not applicable!"
-
-            assert self.moe_quant_config is not None
-
-            return flashinfer_cutlass_moe_fp4(
-                hidden_states=x,
-                w1=layer.w13_weight,
-                w2=layer.w2_weight,
-                topk_weights=topk_weights,
-                topk_ids=topk_ids,
-                quant_config=self.moe_quant_config,
-                inplace=False,  # TODO(shuw): fix later, now output is high prec
+                inplace=False,
                 activation=layer.activation,
                 global_num_experts=layer.global_num_experts,
                 expert_map=layer.expert_map,
                 apply_router_weight_on_input=layer.apply_router_weight_on_input,
             )
-        else:
-            # If no modular kernel is provided, use cutlass_moe_fp4 for TP case
-            # only (no EP).
-            from vllm.model_executor.layers.fused_moe.cutlass_moe import cutlass_moe_fp4
-
-            assert self.moe_quant_config is not None
-            return cutlass_moe_fp4(
-                a=x,
-                w1_fp4=layer.w13_weight,
-                w2_fp4=layer.w2_weight,
-                topk_weights=topk_weights,
-                topk_ids=topk_ids,
-                quant_config=self.moe_quant_config,
-                expert_map=layer.expert_map,
-                apply_router_weight_on_input=layer.apply_router_weight_on_input,
-                # TODO(bnell): derive these from arguments
-                m=x.shape[0],
-                n=layer.w2_weight.shape[2] * 2,
-                k=x.shape[1],
-                e=layer.w13_weight.shape[0],
-            ).to(x.dtype)
 
 
 class CompressedTensorsW8A8Fp8MoEMethod(CompressedTensorsMoEMethod):

vllm/model_executor/layers/quantization/modelopt.py

@@ -15,9 +15,7 @@ from vllm.attention.layer import Attention
 from vllm.logger import init_logger
 from vllm.model_executor.layers.fused_moe.config import (
     FusedMoEQuantConfig,
-    nvfp4_moe_quant_config,
 )
-from vllm.model_executor.layers.fused_moe.fused_marlin_moe import fused_marlin_moe
 from vllm.model_executor.layers.fused_moe.layer import (
     FusedMoE,
     FusedMoEMethodBase,
@@ -30,6 +28,15 @@ from vllm.model_executor.layers.fused_moe.oracle.fp8 import (
     make_fp8_moe_quant_config,
     select_fp8_moe_backend,
 )
+from vllm.model_executor.layers.fused_moe.oracle.nvfp4 import (
+    FLASHINFER_NVFP4_MOE_BACKENDS,
+    NvFp4MoeBackend,
+    convert_to_nvfp4_moe_kernel_format,
+    is_global_sf_supported_for_nvfp4_backend,
+    make_nvfp4_moe_kernel,
+    make_nvfp4_moe_quant_config,
+    select_nvfp4_moe_backend,
+)
 from vllm.model_executor.layers.linear import (
     LinearBase,
     LinearMethodBase,
@@ -45,16 +52,11 @@ from vllm.model_executor.layers.quantization.utils.flashinfer_fp4_moe import (
     build_flashinfer_fp4_cutlass_moe_prepare_finalize,
     flashinfer_trtllm_fp4_moe,
     flashinfer_trtllm_fp4_routed_moe,
-    prepare_static_weights_for_trtllm_fp4_moe,
-    reorder_w1w3_to_w3w1,
     select_nvfp4_gemm_impl,
 )
 from vllm.model_executor.layers.quantization.utils.flashinfer_utils import (
-    FlashinferMoeBackend,
     apply_fi_trtllm_fp8_per_tensor_moe,
     build_flashinfer_fp8_cutlass_moe_prepare_finalize,
-    get_flashinfer_moe_backend,
-    is_flashinfer_supporting_global_sf,
     select_cutlass_fp8_gemm_impl,
 )
 from vllm.model_executor.layers.quantization.utils.fp8_utils import (
@@ -69,7 +71,6 @@ from vllm.model_executor.layers.quantization.utils.marlin_utils_fp4 import (
     apply_fp4_marlin_linear,
     is_fp4_marlin_supported,
     prepare_fp4_layer_for_marlin,
-    prepare_moe_fp4_layer_for_marlin,
 )
 from vllm.model_executor.layers.quantization.utils.quant_utils import (
     GroupShape,
@@ -89,7 +90,6 @@ from vllm.model_executor.parameter import (
     PerTensorScaleParameter,
 )
 from vllm.model_executor.utils import replace_parameter
-from vllm.scalar_type import scalar_types
 from vllm.utils.flashinfer import (
     flashinfer_scaled_fp4_mm,
     has_flashinfer,
@@ -1327,43 +1327,32 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
         quant_config: ModelOptNvFp4Config,
         layer: FusedMoE,
     ) -> None:
-        from vllm.model_executor.layers.quantization.utils.nvfp4_moe_support import (
-            detect_nvfp4_moe_support,  # noqa: E501
-        )
-
         super().__init__(layer.moe_config)
         self.quant_config = quant_config
-        self.layer = layer
-        _nvfp4 = detect_nvfp4_moe_support(self.__class__.__name__)
-        self.cutlass_nvfp4_supported = _nvfp4.cutlass_supported
-        self.allow_flashinfer = _nvfp4.allow_flashinfer
-        self.use_marlin = _nvfp4.use_marlin
-        self.marlin_input_dtype = None
-        self.flashinfer_moe_backend = None
-        if self.allow_flashinfer:
-            self.flashinfer_moe_backend = get_flashinfer_moe_backend()
-            logger.info_once(
-                f"Using FlashInfer {self.flashinfer_moe_backend.value} kernels"
-                " for ModelOptNvFp4FusedMoE."
+        self.nvfp4_backend = select_nvfp4_moe_backend()
+        # TODO: move this type of check into the oracle.
+        if (
+            not self.moe.is_act_and_mul
+            and not self.nvfp4_backend == NvFp4MoeBackend.FLASHINFER_CUTLASS
+        ):
+            raise NotImplementedError(
+                "Non-gated activations are only supported by FlashInfer "
+                "CUTLASS NvFP4 MoE backend."
             )
-        elif self.use_marlin:
-            logger.info_once("Using Marlin for ModelOptNvFp4FusedMoE.")
-        else:
-            logger.info_once("Using Cutlass for ModelOptNvFp4FusedMoE.")
+
+        self.use_global_sf = is_global_sf_supported_for_nvfp4_backend(
+            self.nvfp4_backend
+        )
+        self.kernel: mk.FusedMoEModularKernel | None = None
 
     def maybe_make_prepare_finalize(
         self,
         routing_tables: tuple[torch.Tensor, torch.Tensor, torch.Tensor] | None = None,
     ) -> mk.FusedMoEPrepareAndFinalize | None:
-        if self.use_marlin or (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
+        UNSUPPORTED = [NvFp4MoeBackend.MARLIN, NvFp4MoeBackend.FLASHINFER_TRTLLM]
+        if self.nvfp4_backend in UNSUPPORTED:
             return None
-        elif (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.CUTLASS
-        ):
+        elif self.nvfp4_backend == NvFp4MoeBackend.FLASHINFER_CUTLASS:
             # TP case: avoid convert to ModularKernelMethod - to be refactored.
             if self.moe.dp_size == 1:
                 return None
@@ -1385,7 +1374,7 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
         experts = select_nvfp4_gemm_impl(
             self.moe,
             self.moe_quant_config,
-            allow_flashinfer=self.allow_flashinfer,
+            allow_flashinfer=self.nvfp4_backend in FLASHINFER_NVFP4_MOE_BACKENDS,
         )
         logger.debug_once("Using %s", experts.__class__.__name__)
         return experts
@@ -1405,11 +1394,7 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
         params_dtype: torch.dtype,
         **extra_weight_attrs,
     ):
-        if not self.quant_config.is_checkpoint_nvfp4_serialized:
-            raise ValueError(
-                "NVFP4 quantization was selected, "
-                " dynamic quantization is not supported."
-            )
+        assert self.quant_config.is_checkpoint_nvfp4_serialized
 
         layer.num_experts = num_experts
         layer.params_dtype = params_dtype
@@ -1498,14 +1483,12 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
             {"quant_method": FusedMoeWeightScaleSupported.TENSOR.value}
         )
 
-        use_global_sf = self.allow_flashinfer and is_flashinfer_supporting_global_sf(
-            self.flashinfer_moe_backend
+        global_sf_num_experts = (
+            global_num_experts if self.use_global_sf else num_experts
         )
-        global_scale_num_experts = global_num_experts if use_global_sf else num_experts
-
         w13_input_scale = PerTensorScaleParameter(
             data=torch.empty(
-                global_scale_num_experts,
+                global_sf_num_experts,
                 2 if self.moe.is_act_and_mul else 1,
                 dtype=torch.float32,
             ),
@@ -1514,32 +1497,17 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
         layer.register_parameter("w13_input_scale", w13_input_scale)
 
         w2_input_scale = PerTensorScaleParameter(
-            data=torch.empty(global_scale_num_experts, dtype=torch.float32),
+            data=torch.empty(global_sf_num_experts, dtype=torch.float32),
             weight_loader=weight_loader,
         )
         layer.register_parameter("w2_input_scale", w2_input_scale)
 
     def process_weights_after_loading(self, layer: torch.nn.Module) -> None:
-        # GEMM 1 processing
-        gemm1_weight = layer.w13_weight.data
-        gemm1_weight_scale = layer.w13_weight_scale.data
-
-        if (
-            self.allow_flashinfer
-            and (
-                self.flashinfer_moe_backend == FlashinferMoeBackend.CUTLASS
-                or self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-            )
-            and self.moe.is_act_and_mul
-        ):
-            gemm1_weight, gemm1_weight_scale = reorder_w1w3_to_w3w1(
-                gemm1_weight, gemm1_weight_scale, dim=-2
-            )
-
-        layer.w13_weight = Parameter(gemm1_weight, requires_grad=False)
-        layer.w13_weight_scale = Parameter(gemm1_weight_scale, requires_grad=False)
+        """
+        Convert NVFP4 MoE weights into kernel format and setup the kernel.
+        """
 
-        # Common processing for w13_weight_scale_2
+        # Use a single gscale for w13.
         if self.moe.is_act_and_mul and not torch.allclose(
             layer.w13_weight_scale_2[:, 0], layer.w13_weight_scale_2[:, 1]
         ):
@@ -1547,136 +1515,47 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
                 "w1_weight_scale_2 must match w3_weight_scale_2. "
                 "Accuracy may be affected."
             )
-
         w13_weight_scale_2 = layer.w13_weight_scale_2[:, 0].contiguous()
-        layer.w13_weight_scale_2 = Parameter(w13_weight_scale_2, requires_grad=False)
 
-        # Common processing for input scales and alphas
-        use_global_sf = self.allow_flashinfer and is_flashinfer_supporting_global_sf(
-            self.flashinfer_moe_backend
-        )
-        if use_global_sf:
-            # For backends provide by Flashinfer, the input global scales are
-            # shared across all experts.
-            w13_input_scale = (
-                layer.w13_input_scale.max().to(torch.float32).expand(layer.num_experts)
-            )
-        else:
-            w13_input_scale = layer.w13_input_scale.max(dim=1).values.to(torch.float32)
-        layer.g1_alphas = Parameter(
-            (w13_input_scale * w13_weight_scale_2).to(torch.float32),
-            requires_grad=False,
-        )
-
-        # This is for quantization, so we need to invert it.
-        layer.w13_input_scale_quant = Parameter(
-            (1 / w13_input_scale).to(torch.float32), requires_grad=False
-        )
-
-        # GEMM 2 processing
-        if use_global_sf:
-            # For backends provide by Flashinfer, the input global scales are
-            # shared across all experts.
-            w2_input_scale = (
-                layer.w2_input_scale.max().to(torch.float32).expand(layer.num_experts)
-            )
-        else:
-            w2_input_scale = layer.w2_input_scale
-        layer.g2_alphas = Parameter(
-            (w2_input_scale * layer.w2_weight_scale_2).to(torch.float32),
-            requires_grad=False,
-        )
-
-        # This is for quantization, so we need to invert it.
-        layer.w2_input_scale_quant = Parameter(
-            (1 / w2_input_scale).to(torch.float32), requires_grad=False
+        (
+            w13,
+            w13_scale,
+            w13_scale_2,
+            a13_scale,
+            w2,
+            w2_scale,
+            w2_scale_2,
+            a2_scale,
+        ) = convert_to_nvfp4_moe_kernel_format(
+            nvfp4_backend=self.nvfp4_backend,
+            layer=layer,
+            w13=layer.w13_weight,
+            w13_scale=layer.w13_weight_scale,
+            w13_scale_2=w13_weight_scale_2,
+            a13_scale=layer.w13_input_scale,
+            w2=layer.w2_weight,
+            w2_scale=layer.w2_weight_scale,
+            w2_scale_2=layer.w2_weight_scale_2,
+            a2_scale=layer.w2_input_scale,
+            is_act_and_mul=self.moe.is_act_and_mul,
         )
 
-        # TensorRT-LLM specific processing
-        if (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
-            # Prepare static weights for TRT-LLM kernel
-            # alternate: prepare_static_weight_layouts_for_trtllm_moe
-            (
-                gemm1_weights_fp4_shuffled,
-                gemm1_scales_fp4_shuffled,
-                gemm2_weights_fp4_shuffled,
-                gemm2_scales_fp4_shuffled,
-            ) = prepare_static_weights_for_trtllm_fp4_moe(
-                layer.w13_weight,
-                layer.w2_weight,
-                layer.w13_weight_scale,
-                layer.w2_weight_scale,
-                layer.w2_weight.size(-2),  # hidden_size
-                layer.w13_weight.size(-2) // 2,  # intermediate_size
-                layer.w13_weight.size(0),  # num_experts
-            )
-            logger.debug_once("Finished shuffling weights for TRT-LLM MOE")
-
-            layer.w13_weight = Parameter(
-                gemm1_weights_fp4_shuffled, requires_grad=False
-            )
-            layer.w2_weight = Parameter(gemm2_weights_fp4_shuffled, requires_grad=False)
-            layer.w13_weight_scale = Parameter(
-                gemm1_scales_fp4_shuffled, requires_grad=False
-            )
-            layer.w2_weight_scale = Parameter(
-                gemm2_scales_fp4_shuffled, requires_grad=False
-            )
-
-            # Additional parameter needed for TRT-LLM
-            layer.g1_scale_c = Parameter(
-                (layer.w2_input_scale_quant * layer.g1_alphas).to(torch.float32),
-                requires_grad=False,
-            )
-        elif self.use_marlin:
-            # Marlin processing
-            prepare_moe_fp4_layer_for_marlin(layer)
-            del layer.g1_alphas
-            del layer.g2_alphas
-            del layer.w13_input_scale_quant
-            del layer.w2_input_scale_quant
-        else:
-            # Non-TRT-LLM processing (Cutlass or non-flashinfer)
-            w13_blockscale_swizzled = swizzle_blockscale(layer.w13_weight_scale)
-            layer.w13_weight_scale = Parameter(
-                w13_blockscale_swizzled, requires_grad=False
-            )
-
-            w13_weight = layer.w13_weight
-            intermediate_size_pad = w13_blockscale_swizzled.size(1) - w13_weight.size(1)
-            if intermediate_size_pad:
-                # padding gated activations will require to split w1 and w3
-                # and pad them individually
-                assert not self.moe.is_act_and_mul, (
-                    "The intermediate size required padding, "
-                    "but padding is not implemented for gated activations"
-                )
-
-                layer.w13_weight = Parameter(
-                    torch.nn.functional.pad(
-                        w13_weight, (0, 0, 0, intermediate_size_pad)
-                    ),
-                    requires_grad=False,
-                )
-                layer.w2_weight = Parameter(
-                    torch.nn.functional.pad(
-                        layer.w2_weight, (0, intermediate_size_pad // 2, 0, 0)
-                    ),
-                    requires_grad=False,
-                )
-                layer.w2_weight_scale = Parameter(
-                    torch.nn.functional.pad(
-                        layer.w2_weight_scale, (0, intermediate_size_pad // 16)
-                    ),
-                    requires_grad=False,
-                )
+        replace_parameter(layer, "w13_weight", w13)
+        replace_parameter(layer, "w13_weight_scale", w13_scale)
+        replace_parameter(layer, "w13_weight_scale_2", w13_scale_2)
+        replace_parameter(layer, "w13_input_scale", a13_scale)
+        replace_parameter(layer, "w2_weight", w2)
+        replace_parameter(layer, "w2_weight_scale", w2_scale)
+        replace_parameter(layer, "w2_weight_scale_2", w2_scale_2)
+        replace_parameter(layer, "w2_input_scale", a2_scale)
 
-            w2_blockscale_swizzled = swizzle_blockscale(layer.w2_weight_scale)
-            layer.w2_weight_scale = Parameter(
-                w2_blockscale_swizzled, requires_grad=False
+        self.moe_quant_config = self.get_fused_moe_quant_config(layer)
+        use_dp = self.moe.dp_size > 1
+        if self.moe_quant_config is not None and not use_dp:
+            self.kernel = make_nvfp4_moe_kernel(
+                backend=self.nvfp4_backend,
+                quant_config=self.moe_quant_config,
+                moe_config=self.moe,
             )
 
     def prepare_dp_allgather_tensor(
@@ -1688,7 +1567,8 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
         """Optionally prepare extra tensors to carry through DP allgather/EP."""
         import flashinfer
 
-        a1_gscale = layer.w13_input_scale_quant
+        assert self.moe_quant_config is not None
+        a1_gscale = self.moe_quant_config.a1_gscale
         hidden_states_fp4, hidden_states_sf = flashinfer.fp4_quantize(
             hidden_states,
             a1_gscale,
@@ -1700,19 +1580,14 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
     def get_fused_moe_quant_config(
         self, layer: torch.nn.Module
     ) -> FusedMoEQuantConfig | None:
-        if (
-            self.use_marlin
-            or self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
-            return None
-
-        return nvfp4_moe_quant_config(
-            w1_scale=layer.w13_weight_scale,
+        return make_nvfp4_moe_quant_config(
+            backend=self.nvfp4_backend,
+            w13_scale=layer.w13_weight_scale,
             w2_scale=layer.w2_weight_scale,
-            g1_alphas=layer.g1_alphas,
-            g2_alphas=layer.g2_alphas,
-            a1_gscale=layer.w13_input_scale_quant,
-            a2_gscale=layer.w2_input_scale_quant,
+            w13_scale_2=layer.w13_weight_scale_2,
+            w2_scale_2=layer.w2_weight_scale_2,
+            a13_scale=layer.w13_input_scale,
+            a2_scale=layer.w2_input_scale,
         )
 
     @property
@@ -1725,18 +1600,8 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
         x: torch.Tensor,
         router_logits: torch.Tensor,
     ) -> torch.Tensor | tuple[torch.Tensor, torch.Tensor]:
-        if not self.moe.is_act_and_mul:
-            assert (
-                self.allow_flashinfer
-                and self.flashinfer_moe_backend == FlashinferMoeBackend.CUTLASS
-            ), (
-                "Non-gated activations are only supported by the"
-                " flashinfer CUTLASS backend for modelopt checkpoints"
-            )
-
         if (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
+            self.nvfp4_backend == NvFp4MoeBackend.FLASHINFER_TRTLLM
             and not layer.enable_eplb
         ):
             return flashinfer_trtllm_fp4_moe(
@@ -1762,10 +1627,8 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
         )
 
         # EPLB path
-        if (
-            self.allow_flashinfer
-            and self.flashinfer_moe_backend == FlashinferMoeBackend.TENSORRT_LLM
-        ):
+        if self.nvfp4_backend == NvFp4MoeBackend.FLASHINFER_TRTLLM:
+            assert layer.enable_eplb
             return flashinfer_trtllm_fp4_routed_moe(
                 layer=layer,
                 x=x,
@@ -1774,81 +1637,20 @@ class ModelOptNvFp4FusedMoE(FusedMoEMethodBase):
                 top_k=layer.top_k,
                 global_num_experts=layer.global_num_experts,
             )
-
-        if self.use_marlin:
-            return fused_marlin_moe(
+        else:
+            assert self.kernel is not None
+            return self.kernel(
                 x,
                 layer.w13_weight,
                 layer.w2_weight,
-                None,
-                None,
-                layer.w13_weight_scale,
-                layer.w2_weight_scale,
-                router_logits,
                 topk_weights,
                 topk_ids,
-                global_scale1=layer.w13_weight_scale_2,
-                global_scale2=layer.w2_weight_scale_2,
-                quant_type_id=scalar_types.float4_e2m1f.id,
-                apply_router_weight_on_input=layer.apply_router_weight_on_input,
-                global_num_experts=layer.global_num_experts,
-                expert_map=layer.expert_map,
-                input_dtype=self.marlin_input_dtype,
-            )
-
-        elif self.allow_flashinfer:
-            assert self.flashinfer_moe_backend in (
-                FlashinferMoeBackend.CUTLASS,
-                FlashinferMoeBackend.CUTEDSL,
-            )
-            if self.flashinfer_moe_backend == FlashinferMoeBackend.CUTLASS:
-                from vllm.model_executor.layers.fused_moe.flashinfer_cutlass_moe import (  # noqa: E501
-                    flashinfer_cutlass_moe_fp4,
-                )
-
-                flashinfer_fn_moe_fp4 = flashinfer_cutlass_moe_fp4
-            else:
-                from vllm.model_executor.layers.fused_moe.flashinfer_cutedsl_moe import (  # noqa: E501
-                    flashinfer_cutedsl_moe_fp4,
-                )
-
-                flashinfer_fn_moe_fp4 = flashinfer_cutedsl_moe_fp4
-
-            assert self.moe_quant_config is not None
-            return flashinfer_fn_moe_fp4(
-                hidden_states=x,
-                w1=layer.w13_weight,
-                w2=layer.w2_weight,
-                topk_weights=topk_weights,
-                topk_ids=topk_ids,
-                quant_config=self.moe_quant_config,
                 inplace=False,
                 activation=layer.activation,
                 global_num_experts=layer.global_num_experts,
                 expert_map=layer.expert_map,
                 apply_router_weight_on_input=layer.apply_router_weight_on_input,
             )
-        else:
-            # If no modular kernel is provided, use cutlass_moe_fp4 for TP case
-            # only (no EP).
-            from vllm.model_executor.layers.fused_moe.cutlass_moe import cutlass_moe_fp4
-
-            assert self.moe_quant_config is not None
-            return cutlass_moe_fp4(
-                a=x,
-                w1_fp4=layer.w13_weight,
-                w2_fp4=layer.w2_weight,
-                topk_weights=topk_weights,
-                topk_ids=topk_ids,
-                quant_config=self.moe_quant_config,
-                expert_map=layer.expert_map,
-                apply_router_weight_on_input=layer.apply_router_weight_on_input,
-                # TODO: derive from arguments
-                m=x.shape[0],
-                n=layer.w2_weight.shape[2] * 2,
-                k=x.shape[1],
-                e=layer.w13_weight.shape[0],
-            )
 
 
 ModelOptNvFp4Config.LinearMethodCls = ModelOptNvFp4LinearMethod

vllm/model_executor/layers/quantization/utils/flashinfer_fp4_moe.py

@@ -2,10 +2,13 @@
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 """Utility helpers for NVFP4 + FlashInfer fused-MoE path"""
 
+from typing import TYPE_CHECKING
+
 import torch
 
 import vllm.envs as envs
 import vllm.model_executor.layers.fused_moe.modular_kernel as mk
+from vllm.logger import init_logger
 from vllm.model_executor.layers.fused_moe.config import (
     FusedMoEConfig,
     FusedMoEQuantConfig,
@@ -20,12 +23,23 @@ from vllm.model_executor.layers.fused_moe.flashinfer_cutlass_moe import (
 from vllm.model_executor.layers.fused_moe.flashinfer_cutlass_prepare_finalize import (  # noqa: E501
     create_flashinfer_prepare_finalize,
 )
+from vllm.model_executor.layers.quantization.utils.quant_utils import (
+    swizzle_blockscale,
+)
 from vllm.platforms import current_platform
 from vllm.utils.flashinfer import (
     has_flashinfer_cutedsl_grouped_gemm_nt_masked,
     has_flashinfer_cutlass_fused_moe,
 )
 
+if TYPE_CHECKING:
+    from vllm.model_executor.layers.fused_moe.oracle.nvfp4 import (
+        NvFp4MoeBackend,
+    )
+
+logger = init_logger(__name__)
+
+
 __all__ = [
     "is_flashinfer_fp4_cutlass_moe_available",
     "is_flashinfer_fp4_cutedsl_moe_available",
@@ -273,10 +287,9 @@ def flashinfer_trtllm_fp4_moe(
         hidden_states_fp4, hidden_states_scale_linear_fp4 = x
     else:
         # hidden_states is the already quantized
-        a1_gscale = layer.w13_input_scale_quant
         (hidden_states_fp4, hidden_states_scale_linear_fp4) = flashinfer.fp4_quantize(
             x,
-            a1_gscale,
+            layer.a1_gscale,
             is_sf_swizzled_layout=False,
         )
 
@@ -369,10 +382,9 @@ def flashinfer_trtllm_fp4_routed_moe(
         hidden_states_fp4, hidden_states_scale_linear_fp4 = x
     else:
         # Quantize input to FP4
-        a1_gscale = layer.w13_input_scale_quant
         (hidden_states_fp4, hidden_states_scale_linear_fp4) = flashinfer.fp4_quantize(
             x,
-            a1_gscale,
+            layer.a1_gscale,
             is_sf_swizzled_layout=False,
         )
 
@@ -410,3 +422,93 @@ def flashinfer_trtllm_fp4_routed_moe(
     )[0]
 
     return out
+
+
+def prepare_nvfp4_moe_layer_for_fi_or_cutlass(
+    backend: "NvFp4MoeBackend",
+    layer: torch.nn.Module,
+    w13: torch.Tensor,
+    w13_scale: torch.Tensor,
+    w13_scale_2: torch.Tensor,
+    a13_scale: torch.Tensor,
+    w2: torch.Tensor,
+    w2_scale: torch.Tensor,
+    w2_scale_2: torch.Tensor,
+    a2_scale: torch.Tensor,
+    is_act_and_mul: bool,
+) -> tuple[
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+    torch.Tensor,
+]:
+    # Delayed import for circular dependency avoidance.
+    from vllm.model_executor.layers.fused_moe.oracle.nvfp4 import (
+        NvFp4MoeBackend,
+        is_global_sf_supported_for_nvfp4_backend,
+    )
+
+    assert backend in [
+        NvFp4MoeBackend.VLLM_CUTLASS,
+        NvFp4MoeBackend.FLASHINFER_CUTLASS,
+        NvFp4MoeBackend.FLASHINFER_TRTLLM,
+        NvFp4MoeBackend.FLASHINFER_TRTLLM,
+    ]
+
+    # Reorder [w1, w3] to [w3, w1] for FI NVFP4 MoE kernels.
+    if is_act_and_mul and backend in [
+        NvFp4MoeBackend.FLASHINFER_CUTLASS,
+        NvFp4MoeBackend.FLASHINFER_TRTLLM,
+    ]:
+        w13, w13_scale = reorder_w1w3_to_w3w1(w13, w13_scale)
+
+    # For some FI kernels, the input scales are shared by all experts.
+    if is_global_sf_supported_for_nvfp4_backend(backend):
+        num_experts = w13.shape[0]
+        a13_scale = a13_scale.max().to(torch.float32).expand(num_experts)
+        a2_scale = a2_scale.max().to(torch.float32).expand(num_experts)
+    else:
+        a13_scale = a13_scale.max(dim=1).values.to(torch.float32)
+
+    # Shuffle weights and scales for FI TRTLLM NVFP4 MoE kernels.
+    if backend == NvFp4MoeBackend.FLASHINFER_TRTLLM:
+        w13, w13_scale, w2, w2_scale = prepare_static_weights_for_trtllm_fp4_moe(
+            w13,
+            w2,
+            w13_scale,
+            w2_scale,
+            w2.size(-2),  # hidden_size
+            w13.size(-2) // 2,  # intermediate_size
+            w13.size(0),  # num_experts
+        )
+
+        # We do not need to make this a parameter, because
+        # it is not used during the weight (re)-loading process.
+        layer.g1_scale_c = a13_scale * w13_scale_2 / a2_scale
+        layer.a1_gscale = 1.0 / a13_scale
+        layer.g1_alphas = a13_scale * w13_scale_2
+        layer.g2_alphas = a2_scale * w2_scale_2
+    else:
+        # Swizzle the block scales for other FI NVFP4 MoE kernels.
+        w13_scale = swizzle_blockscale(w13_scale)
+
+        # Apply padding if needed.
+        pad_size = w13_scale.size(1) - w13.size(1)
+        if pad_size > 0:
+            if is_act_and_mul:
+                raise NotImplementedError(
+                    "Intermediate size padding for w1 and w3, for %s "
+                    "NvFp4 backend, but this is not currently supported",
+                    backend.value,
+                )
+            w13 = torch.nn.functional.pad(w13, (0, 0, 0, pad_size))
+            w2 = torch.nn.functional.pad(w2, (0, pad_size // 2, 0, 0))
+            w2_scale = torch.nn.functional.pad(w2_scale, (0, pad_size // 16))
+
+        w2_scale = swizzle_blockscale(w2_scale)
+
+    return w13, w13_scale, w13_scale_2, a13_scale, w2, w2_scale, w2_scale_2, a2_scale

vllm/model_executor/layers/quantization/utils/marlin_utils_fp4.py

@@ -8,6 +8,7 @@ import vllm._custom_ops as ops
 from vllm.logger import init_logger
 from vllm.model_executor.layers.quantization.utils.marlin_utils import (
     USE_FP32_REDUCE_DEFAULT,
+    get_marlin_input_dtype,
     marlin_make_workspace_new,
     marlin_permute_bias,
     marlin_permute_scales,
@@ -226,6 +227,106 @@ def prepare_fp4_layer_for_marlin(
     return
 
 
+def prepare_nvfp4_moe_layer_for_marlin(
+    layer: torch.nn.Module,
+    w13: torch.Tensor,
+    w13_scale: torch.Tensor,
+    w13_scale_2: torch.Tensor,
+    w2: torch.Tensor,
+    w2_scale: torch.Tensor,
+    w2_scale_2: torch.Tensor,
+) -> tuple[
+    torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor, torch.Tensor
+]:
+    logger.warning_once(
+        "Your GPU does not have native support for FP4 computation but "
+        "FP4 quantization is being used. Weight-only FP4 compression will "
+        "be used leveraging the Marlin kernel. This may degrade "
+        "performance for compute-heavy workloads."
+    )
+
+    input_dtype = get_marlin_input_dtype(prefix="")
+    if input_dtype is not None and input_dtype.itemsize == 1:
+        raise RuntimeError("NVFP4 weight + INT8/FP8 activation is not supported.")
+
+    GROUP_SIZE = 16
+    E = layer.num_experts
+    K = layer.hidden_size
+    N = layer.intermediate_size_per_partition
+
+    device = w13.device
+    param_dtype = layer.params_dtype
+    is_a_8bit = input_dtype is not None and input_dtype.itemsize == 1
+
+    # WORKSPACE
+    layer.workspace = marlin_make_workspace_new(device, 4)
+    perm = torch.empty(0, dtype=torch.int, device=device)
+
+    # WEIGHT
+    # Repack weights to marlin format
+    def repack_weight(weight: torch.Tensor, name: str) -> torch.Tensor:
+        tensor_list = []
+        if "w13" in name:
+            size_n, size_k = N * 2, K
+        else:
+            size_n, size_k = K, N
+
+        assert weight.shape == (E, size_n, size_k // 2)
+
+        for i in range(E):
+            qweight = weight[i].view(torch.int32).T.contiguous()
+
+            marlin_qweight = ops.gptq_marlin_repack(
+                b_q_weight=qweight,
+                perm=perm,
+                size_k=size_k,
+                size_n=size_n,
+                num_bits=4,
+                is_a_8bit=is_a_8bit,
+            )
+            tensor_list.append(marlin_qweight)
+
+        return torch.cat([x.unsqueeze(0) for x in tensor_list], 0)
+
+    w13 = repack_weight(w13, "w13")
+    w2 = repack_weight(w2, "w2")
+
+    # WEIGHT SCALES
+    # Permute scales
+    def premute_scales(
+        scales: torch.Tensor, g_scales: torch.Tensor, name: str
+    ) -> tuple[torch.Tensor, torch.Tensor]:
+        scales = scales.to(param_dtype)
+        g_scales = g_scales.to(param_dtype)
+
+        tensor_list = []
+        if "w13" in name:
+            size_n, size_k = N * 2, K
+        else:
+            size_n, size_k = K, N
+
+        for i in range(E):
+            scale = scales[i].T
+            marlin_scales = marlin_permute_scales(
+                s=scale,
+                size_k=size_k,
+                size_n=size_n,
+                group_size=GROUP_SIZE,
+                is_a_8bit=is_a_8bit,
+            )
+            marlin_scales = nvfp4_marlin_process_scales(marlin_scales)
+            tensor_list.append(marlin_scales)
+
+        scales = torch.cat([x.unsqueeze(0) for x in tensor_list], 0)
+        g_scales = nvfp4_marlin_process_global_scale(g_scales)
+        return scales, g_scales
+
+    w13_scale, w13_scale_2 = premute_scales(w13_scale, w13_scale_2, "w13")
+    w2_scale, w2_scale_2 = premute_scales(w2_scale, w2_scale_2, "w2")
+
+    return w13, w13_scale, w13_scale_2, w2, w2_scale, w2_scale_2
+
+
 def prepare_moe_fp4_layer_for_marlin(
     layer: torch.nn.Module, input_dtype: torch.dtype | None = None
 ) -> None: