[Bugfix] Fix Dtypes for Pynccl Wrapper (#33030)

Signed-off-by: Robert Shaw <robshaw@redhat.com>
Co-authored-by: Robert Shaw <robshaw@redhat.com>
(cherry picked from commit 43a013c3)

vllm/distributed/device_communicators/pynccl_wrapper.py

@@ -72,7 +72,8 @@ class ncclDataTypeEnum:
     ncclFloat64 = 8
     ncclDouble = 8
     ncclBfloat16 = 9
-    ncclNumTypes = 10
+    ncclFloat8e4m3 = 10
+    ncclNumTypes = 11
 
     @classmethod
     def from_torch(cls, dtype: torch.dtype) -> int:
@@ -92,9 +93,12 @@ class ncclDataTypeEnum:
             return cls.ncclFloat64
         if dtype == torch.bfloat16:
             return cls.ncclBfloat16
+        if dtype == torch.float8_e4m3fn:
+            return cls.ncclFloat8e4m3
         raise ValueError(
             f"Unsupported dtype {dtype}: should be one of "
-            f"int8, uint8, int32, int64, float16, float32, float64, bfloat16."
+            f"int8, uint8, int32, int64, float16, float32, float64, bfloat16,"
+            " float8e4m3."
         )
 
 

vllm/model_executor/layers/fused_moe/flashinfer_cutlass_prepare_finalize.py

@@ -224,6 +224,8 @@ class FlashInferAllGatherMoEPrepareAndFinalize(FlashInferCutlassMoEPrepareAndFin
                 a1q_scale = None
 
         if is_nvfp4 and a1q_scale is not None:
+            if a1q_scale.element_size() == 1:
+                a1q_scale = a1q_scale.view(torch.uint8)
             a1q_scale = nvfp4_block_scale_interleave(a1q_scale)
 
         return a1q, a1q_scale, None, topk_ids, topk_weights