[HiCache] Add CP support for HiCache (#20977)

Signed-off-by: Shangming Cai <csmthu@gmail.com>

python/sglang/srt/managers/cache_controller.py

@@ -261,6 +261,8 @@ class HiCacheController:
         storage_backend_extra_config: Optional[dict] = None,
         pp_rank: int = 0,
         pp_size: int = 1,
+        attn_cp_rank: int = 0,
+        attn_cp_size: int = 1,
         enable_storage_metrics: bool = False,
     ):
         self.tp_group = tp_group
@@ -280,6 +282,8 @@ class HiCacheController:
         self.storage_backend_type = None
         self.pp_rank = pp_rank
         self.pp_size = pp_size
+        self.attn_cp_rank = attn_cp_rank
+        self.attn_cp_size = attn_cp_size
         self.enable_storage_metrics = enable_storage_metrics
 
         # Default storage page IO functions (may be overridden by attach).
@@ -611,6 +615,8 @@ class HiCacheController:
             tp_size=self.tp_size,
             pp_rank=self.pp_rank,
             pp_size=self.pp_size,
+            attn_cp_rank=self.attn_cp_rank,
+            attn_cp_size=self.attn_cp_size,
             is_mla_model=is_mla_backend,
             enable_storage_metrics=self.enable_storage_metrics,
             is_page_first_layout=self.mem_pool_host.layout == "page_first",