[fix]修复v1 mtp接受率低的问题

vllm/v1/attention/backends/mla/common.py

@@ -546,11 +546,14 @@ class MLACommonMetadataBuilder(AttentionMetadataBuilder[M]):
         device = self.runner.device
         block_table = self.block_table
         block_table_tensor = block_table.get_device_tensor()[:num_reqs]
-        block_table.slot_mapping[:num_actual_tokens].copy_(
-            block_table.slot_mapping_cpu[:num_actual_tokens],
-            non_blocking=True)
-        block_table.slot_mapping[num_actual_tokens:].fill_(-1)
-        slot_mapping = block_table.slot_mapping[:num_actual_tokens]
+
+        slot_mapping = common_attn_metadata.slot_mapping
+        if slot_mapping is None:
+            block_table.slot_mapping[:num_actual_tokens].copy_(
+                block_table.slot_mapping_cpu[:num_actual_tokens],
+                non_blocking=True)
+            block_table.slot_mapping[num_actual_tokens:].fill_(-1)
+            slot_mapping = block_table.slot_mapping[:num_actual_tokens]
 
         query_start_loc = common_attn_metadata.query_start_loc
         seq_lens = common_attn_metadata.seq_lens

vllm/v1/attention/backends/utils.py

@@ -45,6 +45,8 @@ class CommonAttentionMetadata:
     """(batch_size,), record the rejected tokens number in cpu and gpu"""
     num_speculative_tokens: int = 0
     """Number of speculative tokens"""
+    slot_mapping: torch.Tensor = None
+    """(batch_size, seq_len), slot mapping"""
 
 
 M = TypeVar("M")

vllm/v1/spec_decode/eagle.py

@@ -159,6 +159,7 @@ class EagleProposer:
                 num_actual_tokens=num_tokens,
                 max_query_len=max_query_len,
                 num_rejected_tokens=num_rejected_tokens,
+                slot_mapping=target_slot_mapping
             )
 
             assert self.runner is not None