fix UT

Signed-off-by: Chendi Xue <[email protected]>

Author: xuechendi

tests/v1/kv_connector/unit/test_nixl_connector.py

@@ -407,6 +407,7 @@ def _nixl_handshake(
                 # `self.kv_cache_layout` is only forced to HND when vllm engine
                 # is started. We mock HND here.
                 kv_cache_layout="HND",
+                block_size=self.block_size,
             ),
             remote_tp_size=remote_tp_size,
         )
@@ -652,6 +653,7 @@ def test_handshake_fails_on_kv_cache_layout_mismatch(self, dist_init):
                 block_lens=worker.block_len_per_layer,
                 attn_backend_name=worker.backend_name,
                 kv_cache_layout=mismatched_layout,
+                block_size=worker.block_size,
             )
 
             with pytest.raises(RuntimeError):
@@ -706,6 +708,7 @@ def test_handshake_succeed_on_kv_cache_layout_mismatch_with_experimental(
                 block_lens=[i * 2 for i in worker.block_len_per_layer],
                 attn_backend_name=worker.backend_name,
                 kv_cache_layout="HND",
+                block_size=worker.block_size,
             )
 
             # We don't check layout for homogeneous TP and MLA for now, as the

vllm/distributed/kv_transfer/kv_connector/v1/nixl_connector.py

@@ -886,7 +886,7 @@ def __init__(self, vllm_config: VllmConfig, engine_id: str):
 
         # nixl_prepped_dlist_handle.
         self.src_xfer_side_handle: int = 0
-        self.src_xfer_side_handles: dict[int, int] = {}
+        self.src_xfer_side_handles = defaultdict[int, int](int)
         # Map of engine_id -> nixl_prepped_dlist_handle (int)].
         self.dst_xfer_side_handles: dict[EngineId, int] = {}
 
@@ -1647,6 +1647,8 @@ def _process_local_gt_remote(blocks_to_update, block_size_ratio):
             )
             return permuted_blocks
 
+        if len(self.device_kv_caches) == 0:
+            return
         split_k_and_v = not (
             self.use_mla or self._use_pallas or self.kv_topo.is_kv_layout_blocks_first
         )
@@ -1946,7 +1948,9 @@ def _read_blocks(
 
         # Get side handles.
         remote_block_size = self.kv_topo.remote_block_size[dst_engine_id]
-        local_xfer_side_handle = self.src_xfer_side_handles[remote_block_size]
+        local_xfer_side_handle = (
+            self.src_xfer_side_handles[remote_block_size] | self.src_xfer_side_handle
+        )
         remote_xfer_side_handle = self.dst_xfer_side_handles[dst_engine_id]
 
         # NOTE (nicolo) With homogeneous TP, each TP worker loads KV from