[2/N][Refactor] torchair model runner refactor (#2204)

There is lot of torchair code in model runner leading the code hard for
maintenance. We'll create new torchair_model_runner to split torchair
related logic. Following the workflow #2203

What's this PR do:

move `torchair` related logic into `_get_forward_metadata_across_dp` and
override it in torchair model runner


- vLLM version: v0.10.0
- vLLM main:
1b99028069

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

vllm_ascend/torchair/torchair_model_runner.py

@@ -17,6 +17,8 @@
 # Adapted from vllm-project/vllm/vllm/worker/gpu_model_runner.py
 #
 
+from typing import Optional
+
 import torch
 from vllm.config import VllmConfig
 
@@ -27,3 +29,29 @@ class NPUTorchairModelRunner(NPUModelRunner):
 
     def __init__(self, vllm_config: VllmConfig, device: torch.device):
         super().__init__(vllm_config, device)
+
+    def _get_forward_metadata_across_dp_and_pad(
+            self, num_tokens: int, with_prefill: bool, enable_dbo: bool
+    ) -> tuple[int, Optional[torch.Tensor], bool, bool]:
+        if self.dp_size == 1:
+            if not with_prefill:
+                maybe_padded_num_tokens = self.select_torchair_padded_batch_size(
+                    num_tokens)
+                return maybe_padded_num_tokens, None, with_prefill, enable_dbo
+            return num_tokens, None, with_prefill, enable_dbo
+
+        num_tokens_across_dp, with_prefill, enable_dbo = self._get_forward_metadata_across_dp(
+            num_tokens, with_prefill, enable_dbo)
+
+        if not with_prefill:
+            max_num_token = num_tokens_across_dp.max().item()
+            maybe_padded_num_tokens = self.select_torchair_padded_batch_size(
+                max_num_token)
+            num_tokens_across_dp = torch.full((self.dp_size, ),
+                                              maybe_padded_num_tokens,
+                                              dtype=torch.int32,
+                                              device="cpu")
+        else:
+            maybe_padded_num_tokens = num_tokens
+
+        return maybe_padded_num_tokens, num_tokens_across_dp, with_prefill, enable_dbo

vllm_ascend/worker/model_runner_v1.py

@@ -640,26 +640,11 @@ class NPUModelRunner(LoRAModelRunnerMixin):
             self, num_tokens: int, with_prefill: bool, enable_dbo: bool
     ) -> tuple[int, Optional[torch.Tensor], bool, bool]:
         if self.dp_size == 1:
-            if self.torchair_graph_enabled and not with_prefill:
-                maybe_padded_num_tokens = self.select_torchair_padded_batch_size(
-                    num_tokens)
-                return maybe_padded_num_tokens, None, with_prefill, enable_dbo
             return num_tokens, None, with_prefill, enable_dbo
 
-        maybe_padded_num_tokens = num_tokens
         num_tokens_across_dp, with_prefill, enable_dbo = self._get_forward_metadata_across_dp(
             num_tokens, with_prefill, enable_dbo)
-
+        return num_tokens, num_tokens_across_dp, with_prefill, enable_dbo
-        if self.torchair_graph_enabled and not with_prefill:
-            max_num_token = num_tokens_across_dp.max().item()
-            maybe_padded_num_tokens = self.select_torchair_padded_batch_size(
-                max_num_token)
-            num_tokens_across_dp = torch.full((self.dp_size, ),
-                                              maybe_padded_num_tokens,
-                                              dtype=torch.int32,
-                                              device="cpu")
-
-        return maybe_padded_num_tokens, num_tokens_across_dp, with_prefill, enable_dbo
 
     def _check_dbo_is_valid(self, query_lens: torch.Tensor,
                             attn_state: AscendAttentionState,