[CP]: FIx some issue for glm5.2 cp v2 (#33100)

python/sglang/srt/layers/attention/dsa/utils.py

@@ -170,6 +170,13 @@ def cal_padded_tokens(forward_batch: "ForwardBatch"):
     # Consistent with the padding calculation logic in ForwardBatch.prepare_mlp_sync_batch,
     # calculate the actual token length after padding when attn_tp_size > 1 or in the MAX_LEN padding mode.
     from sglang.srt.layers.cp.padding import get_cp_padding_align_size
+    from sglang.srt.layers.cp.utils import is_cp_v2_active
+
+    # CP-v2 already pads each rank-local shard to its physical size
+    if is_cp_v2_active(forward_batch):
+        return forward_batch.attn_cp_metadata.per_rank_actual_token[
+            get_parallel().attn_cp_rank
+        ]
 
     global_num_tokens = forward_batch.global_num_tokens_cpu.copy()
     sync_group_size = len(global_num_tokens)

python/sglang/srt/layers/attention/dsa_backend.py

@@ -3218,6 +3218,11 @@ class DeepseekSparseAttnBackend(
 
             rope_positions = forward_batch.positions
             if dsa_use_prefill_cp(forward_batch):
+                if is_cp_v2_active(forward_batch):
+                    rope_positions = get_cp_strategy().shard_position_ids(
+                        rope_positions, forward_batch
+                    )
+                else:
                     rope_positions = cp_split_and_rebuild_position(
                         forward_batch, rope_positions
                     )

python/sglang/srt/server_args.py

@@ -6203,12 +6203,6 @@ class ServerArgs:
             hf_config = model_config.hf_config
             model_arch = hf_config.architectures[0]
             if model_arch in CP_V2_DEFAULT_MODEL_CLASSES:
-                if getattr(hf_config, "index_share_for_mtp_iteration", False):
-                    # GLM 5.2 (DSA index-share MTP): CP-v2 is not ready for it
-                    # yet, so default the env to off and keep the legacy CP path.
-                    if not envs.SGLANG_ENABLE_CP_V2.is_set():
-                        envs.SGLANG_ENABLE_CP_V2.set(False)
-                else:
                 is_dsa_default_model = is_deepseek_dsa(hf_config)
                 # DSA CP-v2 currently supports only the interleave strategy.
                 enable_default_cp_v2 = not is_dsa_default_model or (