[CI][PD] Add Hybrid SSM integration tests to CI (#37657)

Signed-off-by: NickLucche <nlucches@redhat.com>

.buildkite/test_areas/distributed.yaml

@@ -257,6 +257,17 @@ steps:
     - uv pip install --system -r /vllm-workspace/requirements/kv_connectors.txt
     - CROSS_LAYERS_BLOCKS=True bash v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh
 
+- label: Hyrbid SSM NixlConnector PD accuracy tests (4 GPUs)
+  timeout_in_minutes: 20
+  working_dir: "/vllm-workspace/tests"
+  num_devices: 4
+  source_file_dependencies:
+    - vllm/distributed/kv_transfer/kv_connector/v1/nixl_connector.py
+    - tests/v1/kv_connector/nixl_integration/
+  commands:
+    - uv pip install --system -r /vllm-workspace/requirements/kv_connectors.txt
+    - HYBRID_SSM=1 bash v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh
+
 - label: NixlConnector PD + Spec Decode acceptance (2 GPUs)
   timeout_in_minutes: 30
   device: a100

tests/v1/kv_connector/nixl_integration/config_sweep_accuracy_test.sh

@@ -19,9 +19,9 @@ dp_ep_configs=(
 "DP_EP=1 GPU_MEMORY_UTILIZATION=0.8 PREFILLER_TP_SIZE=2 DECODER_TP_SIZE=2 MODEL_NAMES=deepseek-ai/deepseek-vl2-tiny" # MLA+P-TP2, D-DPEP=2 (TP=1)
 )
 hybrid_ssm_configs=(
-  "ENABLE_HMA_FLAG=1 GPU_MEMORY_UTILIZATION=0.8 MODEL_NAMES=nvidia/NVIDIA-Nemotron-3-Nano-30B-A3B-FP8 VLLM_SERVE_EXTRA_ARGS=--max-model-len,8192,--trust-remote-code"
+  "ENABLE_HMA_FLAG=1 GPU_MEMORY_UTILIZATION=0.8 MODEL_NAMES=ibm-granite/granite-4.0-h-tiny VLLM_SERVE_EXTRA_ARGS=--max-model-len,8192,--trust-remote-code"
   # TODO: (NickLucche) Address async scheduling issue with TP>1 separately as this may impact other models.
-  "ENABLE_HMA_FLAG=1 PREFILLER_TP_SIZE=2 DECODER_TP_SIZE=2 GPU_MEMORY_UTILIZATION=0.8 MODEL_NAMES=nvidia/NVIDIA-Nemotron-3-Nano-30B-A3B-FP8 VLLM_SERVE_EXTRA_ARGS=--max-model-len,8192,--trust-remote-code,--no-async-scheduling"
+  "ENABLE_HMA_FLAG=1 PREFILLER_TP_SIZE=2 DECODER_TP_SIZE=2 GPU_MEMORY_UTILIZATION=0.8 MODEL_NAMES=ibm-granite/granite-4.0-h-tiny VLLM_SERVE_EXTRA_ARGS=--max-model-len,8192,--trust-remote-code,--no-async-scheduling"
 )
 
 # Select config array based on DP_EP env var

tests/v1/kv_connector/nixl_integration/test_accuracy.py

@@ -19,6 +19,7 @@ EXPECTED_VALUES = {
     "deepseek-ai/DeepSeek-V2-Lite-Chat": 0.65,
     "google/gemma-3-4b-it": 0.74,
     "nvidia/NVIDIA-Nemotron-3-Nano-30B-A3B-FP8": 0.84,
+    "ibm-granite/granite-4.0-h-tiny": 0.80,
 }
 
 SIMPLE_PROMPT = (