Drop env-gated CP HiCache page-index validator

The ported 44ba832 added _validate_cp_hicache_page_indices gated on
envs.SGLANG_DEBUG_HICACHE_VALIDATE, but that env was introduced by
97a9f850c (not on this branch). Calling _write_cp / load_cp crashed:

  AttributeError: 'Envs' object has no attribute 'SGLANG_DEBUG_HICACHE_VALIDATE'

The validator is purely defensive (page-alignment holds by construction
in HostKVCache.alloc and CpSharedKVLayout.logical_locs_to_physical), so
remove the function entirely along with its 4 call sites in _write_cp
and load_cp. The wrapping try/except blocks existed solely to free
allocations when validation raised; with no raising call inside, they
become dead and are removed too. Stale imports (envs,
validate_page_aligned_token_indices) dropped.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

python/sglang/srt/managers/cache_controller.py

@@ -32,7 +32,6 @@ from sglang.srt.distributed import (
     get_tensor_model_parallel_rank,
     get_tensor_model_parallel_world_size,
 )
-from sglang.srt.environ import envs
 from sglang.srt.layers.dp_attention import (
     get_attention_dp_rank,
     get_attention_tp_rank,
@@ -41,7 +40,6 @@ from sglang.srt.layers.dp_attention import (
 )
 from sglang.srt.mem_cache.cp_shared_kv_layout import CpSharedKVLayout
 from sglang.srt.mem_cache.memory_pool import MLATokenToKVPool, NSATokenToKVPool
-from sglang.srt.mem_cache.page_index_utils import validate_page_aligned_token_indices
 from sglang.srt.utils import get_device_module
 
 logger = logging.getLogger(__name__)
@@ -832,18 +830,6 @@ class HiCacheController:
         event.record()
         self.ack_load_queue.append(HiCacheAck(event, event, [node_id]))
 
-    def _validate_cp_hicache_page_indices(
-        self,
-        host_indices: torch.Tensor,
-        device_indices: torch.Tensor,
-    ) -> None:
-        if not envs.SGLANG_DEBUG_HICACHE_VALIDATE.get():
-            return
-        validate_page_aligned_token_indices(
-            device_indices, self.page_size, "physical_device_indices"
-        )
-        validate_page_aligned_token_indices(host_indices, self.page_size, "host_indices")
-
     def _write_cp(
         self,
         device_indices: torch.Tensor,
@@ -922,17 +908,6 @@ class HiCacheController:
                 return HiCacheWriteFailure(
                     required_host_slots=len(physical_device_indices)
                 )
-        try:
-            self._validate_cp_hicache_page_indices(host_indices, physical_device_indices)
-            if draft_host_indices is not None:
-                self._validate_cp_hicache_page_indices(
-                    draft_host_indices, physical_device_indices
-                )
-        except Exception:
-            self.mem_pool_host.free(host_indices)
-            if draft_host_indices is not None:
-                self.draft_mem_pool_host.free(draft_host_indices)
-            raise
 
         self.write_queue.append(
             CacheOperation(host_indices, physical_device_indices, node_id, priority)
@@ -1091,21 +1066,9 @@ class HiCacheController:
 
         host_indices = torch.cat(host_chunks)
         physical_device_indices = torch.cat(physical_chunks)
-        try:
-            self._validate_cp_hicache_page_indices(host_indices, physical_device_indices)
-        except Exception:
-            self.mem_pool_device_allocator.free(device_indices)
-            raise
         draft_host_indices = None
         if self.has_draft_hicache:
             draft_host_indices = torch.cat(draft_host_chunks)
-            try:
-                self._validate_cp_hicache_page_indices(
-                    draft_host_indices, physical_device_indices
-                )
-            except Exception:
-                self.mem_pool_device_allocator.free(device_indices)
-                raise
 
         self.load_queue.append(
             CacheOperation(