[Attention][Kernel]moe support for llama4 and mllama4 (#740)

### What this PR does / why we need it?
moe support for llama4 and mllama4 in vllm-ascend

### Does this PR introduce _any_ user-facing change?
no
### How was this patch tested?
start sever:
python -m vllm.entrypoints.openai.api_server --model
/data/nfs/benchmark/tokenizer/Llama-4-Scout-17B-16E-Instruct \
--max-num-seqs=256 \
--max-model-len=8192 \
--tensor-parallel-size=8 \
--block-size=128 \
--dtype bfloat16 \
--host=0.0.0.0 \
--port=8000 \
--gpu-memory-utilization=0.9 \
--trust-remote-code

client:
python online_server.py --model-path
/data/nfs/benchmark/tokenizer/Llama-4-Scout-17B-16E-Instruct
--image-path /data/nfs/w60040464/cherry_blossom.jpg --docker-ip
7.242.108.253 --served-port 8000 --text "what is the content of this
image?"

result:
{'id': 'chatcmpl-2b709a5d2e1a4017991ec4ba8248686a', 'object':
'chat.completion', 'created': 1747056823, 'model':
'/data/nfs/benchmark/tokenizer/Llama-4-Scout-17B-16E-Instruct',
'choices': [{'index': 0, 'message': {'role': 'assistant',
'reasoning_content': None, 'content': 'The image depicts a tower, likely
Tokyo Skytree, framed by branches of a cherry blossom tree. The tower is
white and has a distinctive shape, with a large sphere at the top and a
long, thin spire extending from it. The branches of the cherry blossom
tree are in the foreground, with pink flowers blooming on them. The
background is a clear blue sky.\n\n**Key Features:**\n\n* **Tower:**
White, spherical shape at the top, long thin spire\n', 'tool_calls':
[]}, 'logprobs': None, 'finish_reason': 'length', 'stop_reason': None}],
'usage': {'prompt_tokens': 2340, 'total_tokens': 2440,
'completion_tokens': 100, 'prompt_tokens_details': None},
'prompt_logprobs': None}

Signed-off-by: chenxu <chenxu68@huawei.com>
Co-authored-by: chenxu <chenxu68@huawei.com>
Co-authored-by: evian <eviantai@u.nus.edu>

vllm_ascend/attention/attention.py

@@ -708,6 +708,7 @@ class AscendAttentionBackendImpl(AttentionImpl):
         blocksparse_params: Optional[Dict[str, Any]] = None,
         logits_soft_cap: Optional[float] = None,
         attn_type: str = AttentionType.DECODER,
+        use_irope: bool = False,
     ) -> None:
         self.num_heads = num_heads
         self.head_size = head_size

vllm_ascend/attention/attention_v1.py

@@ -174,6 +174,7 @@ class AscendAttentionBackendImpl(AttentionImpl):
         blocksparse_params: Optional[Dict[str, Any]] = None,
         logits_soft_cap: Optional[float] = None,
         attn_type: str = AttentionType.DECODER,
+        use_irope: bool = False,
     ) -> None:
         self.num_heads = num_heads
         self.head_size = head_size

vllm_ascend/ops/common_fused_moe.py

@@ -55,13 +55,15 @@ def forward_oot(
         e_score_correction_bias=e_score_correction_bias,
     )
 
-    return fused_experts(hidden_states=x,
-                         w1=layer.w13_weight,
-                         w2=layer.w2_weight,
-                         topk_weights=topk_weights,
-                         topk_ids=topk_ids,
-                         top_k=top_k,
-                         expert_map=expert_map)
+    return fused_experts(
+        hidden_states=x,
+        w1=layer.w13_weight,
+        w2=layer.w2_weight,
+        topk_weights=topk_weights,
+        topk_ids=topk_ids,
+        top_k=top_k,
+        expert_map=expert_map,
+        apply_router_weight_on_input=apply_router_weight_on_input)
 
 
 UnquantizedFusedMoEMethod.forward_oot = forward_oot

vllm_ascend/ops/fused_moe.py

@@ -153,6 +153,7 @@ def fused_experts(
     topk_ids: torch.Tensor,
     top_k: int,
     expert_map: torch.Tensor = None,
+    apply_router_weight_on_input: bool = False,
 ) -> torch.Tensor:
     """
     Fused experts with top-k routing.
@@ -191,6 +192,15 @@ def fused_experts(
     # assert dtype in [torch.float32, torch.float16, torch.bfloat16
     #                  ], "Only float32, float16, and bfloat16 are supported"
 
+    if apply_router_weight_on_input:
+        assert (topk_weights.dim() == 2
+                ), "`topk_weights` should be in shape (num_tokens, topk)"
+        _, topk = topk_weights.shape
+        assert (
+            topk == 1
+        ), "Only support topk=1 when `apply_router_weight_on_input` is True"
+        hidden_states = hidden_states * topk_weights.to(hidden_states.dtype)
+
     if expert_map is not None:
         # Generate token indices and flatten
         token_indices = (torch.arange(num_tokens,
@@ -292,6 +302,8 @@ def fused_experts(
             torch.zeros_like(weighted_down_out)).to(dtype)
         final_hidden_states.index_add_(0, sorted_token_indices, valid_output)
     else:
+        scales = torch.ones_like(
+            topk_weights) if apply_router_weight_on_input else topk_weights
         # TODO: Reorder device memory 2 times here, replace the current
         # implementation here when suitable operators become available.
         final_hidden_states = torch_npu.npu_moe_finalize_routing(
@@ -299,7 +311,7 @@ def fused_experts(
             skip1=None,
             skip2=None,
             bias=None,
-            scales=topk_weights,
+            scales=scales,
             expanded_src_to_dst_row=expanded_row_idx,
             export_for_source_row=topk_ids,
         )
@@ -366,9 +378,6 @@ def select_experts(
     Raises:
         ValueError: If an unsupported scoring function is provided.
     """
-    if custom_routing_function is not None:
-        raise NotImplementedError(
-            "Custom routing function is not supported now")
 
     if scoring_func == "softmax":
         # NOTE: vLLM use dtype=torch.float here
@@ -405,9 +414,18 @@ def select_experts(
                                                 k=top_k,
                                                 dim=-1,
                                                 sorted=False)
-    else:
+    elif custom_routing_function is None:
         topk_weights, topk_ids = topk_weights.topk(top_k, dim=-1)
         topk_weights = topk_weights.to(hidden_states.dtype)
+    else:
+        topk_weights, topk_ids = custom_routing_function(
+            hidden_states=hidden_states,
+            gating_output=router_logits,
+            topk=top_k,
+            renormalize=renormalize)
+        # Required by npu_moe_init_routing
+        topk_ids = topk_ids.to(torch.int32)
+        return topk_weights, topk_ids
 
     # Required by npu_moe_init_routing
     topk_ids = topk_ids.to(torch.int32)