[Bugfix] Fix the Eagle3 inference failure issue. (#4721)

### What this PR does / why we need it?
Fix the Eagle3 inference failure issue.
error message: "EngineCore encountered an issue. See stack trace (above)
for the root cause."

Fixes https://github.com/vllm-project/vllm-ascend/issues/4323

### How was this patch tested?
`vllm serve /nfs/1_AscendPackage/05_weights_public/Qwen3-32B \
--served-model-name Qwen3-32B \ -tp 4 \ --host "0.0.0.0" \ --port "8000"
\ --trust-remote-code \ --speculative-config
'{"method":"eagle3","model":"/home/scd/qwen3_32b_eagle3/","num_speculative_tokens":4,"draft_tensor_parallel_size":1}'
\ --max-num-batched-tokens 4096 \ --max-model-len 4096`

```
curl http://localhost:8000/v1/completions \
    -H "Content-Type: application/json" \
    -d '{
        "model": "Qwen3-32B",
        "prompt": "hi, where is the capital of France?",
        "max_tokens": 10,
        "temperature": 0
    }' | python3 -m json.tool
```

vLLM version: v0.11.0
vLLM-ascend version: v0.11.0rc2

Signed-off-by: 17764591921 <sunchend@outlook.com>

vllm_ascend/spec_decode/eagle_proposer.py

@@ -72,7 +72,7 @@ class EagleProposer(Proposer):
                                    dtype=torch.int32)
         attn_mask_len = self.vllm_config.model_config.max_model_len
         self.attn_mask_builder = AttentionMaskBuilder(
-            attn_mask_len, self.vllm_config.model_config.dtype)
+            attn_mask_len, self.vllm_config.model_config.dtype, device=device)
 
     def load_model(self, model: nn.Module) -> None:
         target_attn_layer_names = set(
@@ -424,9 +424,7 @@ class EagleProposer(Proposer):
 
         query_lens = cu_num_tokens[1:] - cu_num_tokens[:-1]
         max_query_len = query_lens.max().item()
-        attn_mask = self.attn_mask_builder.get_splitfuse_attn_mask(
-            seq_lens, target_positions, self.vllm_config.model_config.dtype,
-            self.device)
+        attn_mask = self.runner.attn_mask
 
         common_attn_metadata = AscendCommonAttentionMetadata(
             query_start_loc=cu_num_tokens.to(device),
@@ -506,9 +504,15 @@ class EagleProposer(Proposer):
         attn_metadata.num_actual_tokens = batch_size
         attn_metadata.max_query_len = 1
         attn_metadata.query_start_loc = self.arange[:batch_size + 1]
+        attn_metadata.query_start_loc_list = attn_metadata.query_start_loc[
+            1:].tolist()
+        attn_metadata.num_decodes, attn_metadata.num_prefills, attn_metadata.num_decode_tokens, attn_metadata.num_prefill_tokens = 0, batch_size, 0, batch_size
+        attn_metadata.num_actual_tokens_pcp_padded = attn_metadata.num_decode_tokens + attn_metadata.num_prefill_tokens
         query_lens.fill_(1)
         attn_metadata.query_lens = query_lens
 
+        attn_metadata.actual_seq_lengths_q = [1 + i for i in range(batch_size)]
+        attn_metadata.seq_lens_list = seq_lens.tolist()
         attn_metadata.attn_state = AscendAttentionState.ChunkedPrefill
         for now_speculative in range(
                 self.vllm_config.speculative_config.num_speculative_tokens -
@@ -535,6 +539,9 @@ class EagleProposer(Proposer):
             # TODO: Increment the sequence lengths.
 
             attn_metadata.seq_lens += 1
+            attn_metadata.seq_lens_list = [
+                _ + 1 for _ in attn_metadata.seq_lens_list
+            ]
             # TODO: Consider max model length.
             # attn_metadata.max_seq_len = min(attn_metadata.max_seq_len,
             #                                 self.max_model_len)

vllm_ascend/utils.py

@@ -61,6 +61,7 @@ _IS_VL_MODEL = None
 _ENABLE_SP = None
 _HAS_LAYER_IDX = None
 _ENABLE_NZ = None
+_IS_EAGLE_MODE = None
 
 
 def is_310p():
@@ -73,14 +74,20 @@ def is_310p():
 
 def is_enable_nz(dtype: Optional[torch.dtype] = torch.int8,
                  vllm_config: Optional[VllmConfig] = None) -> bool:
-    global _ENABLE_NZ
+    global _ENABLE_NZ, _IS_EAGLE_MODE
     if _ENABLE_NZ is None:
         if not vllm_config:
             raise ValueError(
                 "vllm_config must be provided when _ENABLE_NZ is None")
         _ENABLE_NZ = envs_ascend.VLLM_ASCEND_ENABLE_NZ and vllm_config.model_config.hf_config.model_type != "qwen3_next"
+
+        _IS_EAGLE_MODE = (
+            vllm_config.speculative_config is not None and 
+            getattr(vllm_config.speculative_config, 'method', None) in ("eagle", "eagle3")
+        )
+
     if dtype in [torch.float16, torch.bfloat16]:
-        return False
+        return _ENABLE_NZ if _IS_EAGLE_MODE else False
     return _ENABLE_NZ