[Hardware][AMD][CI][Bugfix] Fix regressions from deprecated env vars (#32837)

Signed-off-by: Matthew Wong <Matthew.Wong2@amd.com>

.buildkite/test-amd.yaml

@@ -1475,7 +1475,7 @@ steps:
     - tests/v1/kv_connector/nixl_integration/
   commands:
     - uv pip install --system -r /vllm-workspace/requirements/kv_connectors_rocm.txt
-    - bash v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh --attention-backend ROCM_ATTN
+    - ROCM_ATTN=1 bash v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh
 
 - label: DP EP NixlConnector PD accuracy tests (Distributed) # 15min
   mirror_hardwares: [amdexperimental, amdproduction]
@@ -1489,7 +1489,7 @@ steps:
     - tests/v1/kv_connector/nixl_integration/
   commands:
     - uv pip install --system -r /vllm-workspace/requirements/kv_connectors_rocm.txt
-    - DP_EP=1 bash v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh --attention-backend ROCM_ATTN
+    - DP_EP=1 ROCM_ATTN=1 bash v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh
 
 ##### multi gpus test #####
 ##### A100 test #####

tests/v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh

@@ -43,7 +43,12 @@ run_tests() {
 }
 
 # Run tests
-run_tests "default backend" ""
+if [[ -n "${ROCM_ATTN:-}" ]]; then
+  echo "ROCM_ATTN is set, running with --attention-backend ROCM_ATTN"
+  run_tests "ROCM_ATTN backend" "--attention-backend ROCM_ATTN"
+else
+  run_tests "default backend" ""
+fi
 
 # Check if FLASHINFER is set (non-empty)
 if [[ -n "${FLASHINFER:-}" ]]; then

vllm/platforms/rocm.py

@@ -293,10 +293,13 @@ class RocmPlatform(Platform):
                 return AttentionBackendEnum.ROCM_AITER_FA.get_path()
 
             # Priority 3: Check for ROCM_ATTN (prefill-decode split)
-            from vllm.config import get_current_vllm_config
+            from vllm.config import get_current_vllm_config_or_none
 
-            vllm_config = get_current_vllm_config()
-            if vllm_config.attention_config.use_prefill_decode_attention:
+            vllm_config = get_current_vllm_config_or_none()
+            if (
+                vllm_config is not None
+                and vllm_config.attention_config.use_prefill_decode_attention
+            ):
                 logger.info("Using Rocm Attention backend.")
                 return AttentionBackendEnum.ROCM_ATTN.get_path()