[Feat] QWen-1M context support[2/2]: Update block sparse attention backend (#5949)

python/sglang/srt/models/qwen2.py

@@ -107,6 +107,7 @@ class Qwen2Attention(nn.Module):
         rope_scaling: Optional[Dict[str, Any]] = None,
         max_position_embeddings: int = 32768,
         quant_config: Optional[QuantizationConfig] = None,
+        dual_chunk_attention_config: Optional[dict[str, Any]] = None,
         prefix: str = "",
     ) -> None:
         super().__init__()
@@ -158,6 +159,7 @@ class Qwen2Attention(nn.Module):
             max_position=max_position_embeddings,
             base=rope_theta,
             rope_scaling=rope_scaling,
+            dual_chunk_attention_config=dual_chunk_attention_config,
         )
         self.attn = RadixAttention(
             self.num_heads,
@@ -198,6 +200,9 @@ class Qwen2DecoderLayer(nn.Module):
         rope_scaling = getattr(config, "rope_scaling", None)
         max_position_embeddings = getattr(config, "max_position_embeddings", 32768)
         head_dim = getattr(config, "head_dim", None)
+        dual_chunk_attention_config = getattr(
+            config, "dual_chunk_attention_config", None
+        )
         self.self_attn = Qwen2Attention(
             hidden_size=self.hidden_size,
             num_heads=config.num_attention_heads,
@@ -208,6 +213,7 @@ class Qwen2DecoderLayer(nn.Module):
             rope_scaling=rope_scaling,
             max_position_embeddings=max_position_embeddings,
             quant_config=quant_config,
+            dual_chunk_attention_config=dual_chunk_attention_config,
             prefix=add_prefix("self_attn", prefix),
         )
         self.mlp = Qwen2MLP(