[TRTLLM-12154][test] Move model path helper to common

Signed-off-by: Brian Nguyen <brnguyen@nvidia.com>

Author: brnguyen2

tests/integration/defs/common.py

@@ -56,6 +56,15 @@ def _war_check_output(*args, **kwargs):
     return venv.run_cmd(cmd, caller=_war_check_output, env=env, **kwargs)
 
 
+def resolve_llm_model_path(model_path: str) -> str:
+    """Resolve a model subpath relative to the test LLM model root."""
+    if os.path.isabs(model_path):
+        return model_path
+
+    from .conftest import llm_models_root
+    return os.path.join(llm_models_root(), model_path)
+
+
 def venv_mpi_check_call(venv, mpi_cmd, python_cmd, **kwargs):
     """
     This function WAR check_call() to run python_cmd with mpi.

tests/integration/defs/disaggregated/test_disaggregated.py

@@ -31,7 +31,8 @@
 import pytest
 import yaml
 from defs.common import get_free_port_in_ci as get_free_port
-from defs.common import parse_gsm8k_output, wait_for_server
+from defs.common import (parse_gsm8k_output, resolve_llm_model_path,
+                         wait_for_server)
 from defs.conftest import (get_sm_version, llm_models_root, skip_arm,
                            skip_no_hopper, skip_pre_blackwell, skip_pre_hopper)
 from defs.trt_test_alternative import check_call, check_output, print_info
@@ -343,13 +344,6 @@ def setup_model_symlink(llm_venv, model_root, dest_subpath):
         os.symlink(model_root, dst, target_is_directory=True)
 
 
-def _resolve_llm_model_path(model_path: str) -> str:
-    """Resolve a model subpath relative to the test LLM model root."""
-    if os.path.isabs(model_path):
-        return model_path
-    return os.path.join(llm_models_root(), model_path)
-
-
 ClientTestSet = namedtuple('ClientTestSet', [
     'completion', 'completion_streaming', 'chat', 'chat_streaming',
     'verify_completion', 'verify_streaming_completion', 'verify_chat',
@@ -636,7 +630,7 @@ def setup_disagg_cluster(
     if isinstance(speculative_config, dict):
         speculative_model = speculative_config.get("speculative_model")
         if speculative_model:
-            speculative_config["speculative_model"] = _resolve_llm_model_path(
+            speculative_config["speculative_model"] = resolve_llm_model_path(
                 speculative_model)
 
     disagg_cluster = get_default_disagg_cluster_config()
@@ -670,7 +664,7 @@ def setup_disagg_cluster(
     # Launch workers
     model = model_name or config.get("model")
     if model:
-        model = _resolve_llm_model_path(model)
+        model = resolve_llm_model_path(model)
     ctx_workers = []
     gen_workers = []
     disagg_server = None
@@ -2317,7 +2311,7 @@ def test_disaggregated_gpt_oss_120b_harmony(disaggregated_test_root,
 def test_disaggregated_qwen3_32b_fp8(disaggregated_test_root,
                                      disaggregated_example_root, llm_venv,
                                      model_path):
-    model_dir = _resolve_llm_model_path(model_path)
+    model_dir = resolve_llm_model_path(model_path)
     setup_model_symlink(llm_venv, model_dir, model_path)
 
     run_disaggregated_test(disaggregated_example_root,
@@ -2407,7 +2401,7 @@ def test_disaggregated_stress_test(disaggregated_test_root,
     # Unpack configuration from dataclass
     model_path = test_config.model_path
     test_desc = test_config.test_desc
-    model_dir = _resolve_llm_model_path(model_path)
+    model_dir = resolve_llm_model_path(model_path)
     setup_model_symlink(llm_venv, model_dir, model_path)
 
     config_file = get_test_config(test_desc, disaggregated_example_root,