From a2cb08b3d50ecbe3dbc18227aaa774f9b309683e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nicol=C3=B2=20Lucchesi?= <nlucches@redhat.com>
Date: Wed, 24 Jun 2026 15:14:05 +0200
Subject: [PATCH] [Misc][PD] Disable bidirectional xfer mode for
 NixlPushConnector (#46473)

Signed-off-by: NickLucche <nicolo.lucchesi@mistral.ai>
---
 .../kv_transfer/kv_connector/v1/nixl/push_scheduler.py        | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/vllm/distributed/kv_transfer/kv_connector/v1/nixl/push_scheduler.py b/vllm/distributed/kv_transfer/kv_connector/v1/nixl/push_scheduler.py
index dc976ae3a39..8b437096788 100644
--- a/vllm/distributed/kv_transfer/kv_connector/v1/nixl/push_scheduler.py
+++ b/vllm/distributed/kv_transfer/kv_connector/v1/nixl/push_scheduler.py
@@ -67,6 +67,10 @@ class NixlPushConnectorScheduler(NixlBaseConnectorScheduler):
         kv_cache_config: KVCacheConfig,
     ):
         super().__init__(vllm_config, engine_id, kv_cache_config)
+        if self.is_bidirectional_kv_xfer_enabled:
+            raise NotImplementedError(
+                "Bidirectional KV transfer is not supported for NIXL push connector."
+            )
 
         # D-side: registration data to pass to D workers via metadata on
         # the next ``build_connector_meta`` call.