[Feat]enable sfa cp for dsv3.2 (#4702)

### What this PR does / why we need it?
RFC: https://github.com/vllm-project/vllm/issues/30055

### How was this patch tested?
1. enable flashcommon1
export VLLM_ASCEND_ENABLE_FLASHCOMM1=1
2. enable sfa-cp
--additional-config '{ "enable_sfa_cp": true }' \

- vLLM version: v0.12.0
- vLLM main:
ad32e3e19c

Signed-off-by: AlvisGong <gwly0401@163.com>
Co-authored-by: clrs97 <524936896@qq.com>
Co-authored-by: zzhx1 <zzh_201018@outlook.com>
Co-authored-by: hwhaokun <haokun0405@163.com>
Co-authored-by: wangxiyuan <wangxiyuan1007@gmail.com>

vllm_ascend/distributed/parallel_state.py

@@ -9,7 +9,7 @@ from vllm.distributed.parallel_state import (GroupCoordinator, get_dp_group,
 
 import vllm_ascend.envs as envs_ascend
 from vllm_ascend.ascend_config import get_ascend_config
-from vllm_ascend.utils import flashcomm2_enable
+from vllm_ascend.utils import enable_sp, flashcomm2_enable
 
 # Currently, mc2 op need their own group coordinator.
 _MC2: Optional[GroupCoordinator] = None
@@ -19,6 +19,7 @@ _LMTP: Optional[GroupCoordinator] = None
 _P_TP: Optional[GroupCoordinator] = None
 _FLASHCOMM2_OTP: Optional[GroupCoordinator] = None
 _FLASHCOMM2_ODP: Optional[GroupCoordinator] = None
+_SHARED_WEIGHT: Optional[GroupCoordinator] = None
 
 
 def get_mc2_group() -> GroupCoordinator:
@@ -48,6 +49,13 @@ def get_flashcomm2_odp_group() -> GroupCoordinator:
     return _FLASHCOMM2_ODP
 
 
+def get_shared_weight_group() -> GroupCoordinator:
+    assert _SHARED_WEIGHT is not None, (
+        "output shared weight parallel group for flashcomm2 is not initialized"
+    )
+    return _SHARED_WEIGHT
+
+
 def get_mlp_tp_group() -> GroupCoordinator:
     assert _MLP_TP is not None, ("mlp group is not initialized")
     return _MLP_TP
@@ -226,6 +234,18 @@ def init_ascend_model_parallel(parallel_config: ParallelConfig, ):
                 backend,
                 group_name="flashcomm2_odp")
 
+    vllm_config = get_current_vllm_config()
+    # TODO: Check if the model is Deepseek V3.2 with enabled SFA CP and activated shared weights. It will then be normalized within the PCP parameters. -- clrs97
+    is_ds_v32 = hasattr(vllm_config.model_config.hf_config, "index_topk")
+    if enable_sp() and is_ds_v32:
+        global _SHARED_WEIGHT
+        group_ranks = [list(range(torch.distributed.get_world_size()))]
+        _SHARED_WEIGHT = init_model_parallel_group(
+            group_ranks,
+            get_world_group().local_rank,
+            backend,
+            group_name="CP_shared_weight")
+
 
 def get_mlp_tensor_model_parallel_world_size():
     """Return world size for the tensor model parallel group."""
@@ -274,3 +294,8 @@ def destroy_ascend_model_parallel():
     ).flashcomm2_oproj_tensor_parallel_size != 1:
         _FLASHCOMM2_ODP.destroy()
         _FLASHCOMM2_ODP = None
+
+    global _SHARED_WEIGHT
+    if _SHARED_WEIGHT:
+        _SHARED_WEIGHT.destroy()
+    _SHARED_WEIGHT = None