set default rdma-core for distros with old rdma-core packages to force source build

Author: mcgov

lisa/microsoft/testsuites/dpdk/common.py

@@ -508,7 +508,7 @@ class TestpmdForwardMode(str, Enum):
 
 _dpdk_default_source_dict = {
     "Ubuntu": {
-        "20.4.0": "v24.11",
+        "20.4.0": "v25.11",
         "22.4.0": "v24.11",
         "24.4.0": "v24.11",
         "25.4.0": "v25.11",

lisa/microsoft/testsuites/dpdk/dpdkutil.py

@@ -514,7 +514,7 @@ def initialize_node_resources(
         )
     except UnsupportedDistroException as err:
         raise SkippedException(err)
-    rdma_source = variables.get("rdma_source", "")
+    rdma_source = variables.get("rdma_source", RDMA_CORE_MANA_DEFAULT_SOURCE)
     rdma_branch = variables.get("rdma_branch", "")
     force_net_failsafe_pmd = variables.get("dpdk_force_net_failsafe_pmd", False)
     log.info(