env_process: Refactor transparent huge pages setup/cleanup

Rewriting the transparent huge pages setup/cleanup steps into a setuper
and registering it into the env_process setup_manager.

This is a patch from a larger patch series refactoring the env_process
preprocess and postprocess functions. In each of these patches, a
pre/post process step is identified and replaced with a Setuper subclass
so the following can finally be met:
    - Only cleanup steps of successful setup steps are run to avoid
      possible environment corruption or hard to read errors.
    - Running setup/cleanup steps symmetrically during env pre/post
      process.
    - Reduce explicit pre/post process function code length.

Signed-off-by: Beñat Gartzia Arruabarrena <bgartzia@redhat.com>

Author: bgartzi

virttest/env_process.py

@@ -46,7 +46,7 @@
 from virttest.test_setup.gcov import ResetQemuGCov
 from virttest.test_setup.kernel import ReloadKVMModules
 from virttest.test_setup.libvirt_setup import LibvirtdDebugLogConfig
-from virttest.test_setup.memory import HugePagesSetup
+from virttest.test_setup.memory import HugePagesSetup, TransparentHugePagesSetup
 from virttest.test_setup.migration import MigrationEnvSetup
 from virttest.test_setup.networking import (
     BridgeConfig,
@@ -1020,6 +1020,7 @@ def preprocess(test, params, env):
     _setup_manager.register(CheckLibvirtVersion)
     _setup_manager.register(LogVersionInfo)
     _setup_manager.register(HugePagesSetup)
+    _setup_manager.register(TransparentHugePagesSetup)
     _setup_manager.do_setup()
 
     vm_type = params.get("vm_type")
@@ -1028,10 +1029,6 @@ def preprocess(test, params, env):
 
     libvirtd_inst = None
 
-    if params.get("setup_thp") == "yes":
-        thp = test_setup.TransparentHugePageConfig(test, params, env)
-        thp.setup()
-
     if params.get("setup_ksm") == "yes":
         ksm = test_setup.KSMConfig(params, env)
         ksm.setup(env)
@@ -1513,14 +1510,6 @@ def postprocess(test, params, env):
     libvirtd_inst = None
     vm_type = params.get("vm_type")
 
-    if params.get("setup_thp") == "yes":
-        try:
-            thp = test_setup.TransparentHugePageConfig(test, params, env)
-            thp.cleanup()
-        except Exception as details:
-            err += "\nTHP cleanup: %s" % str(details).replace("\\n", "\n  ")
-            LOG.error(details)
-
     if params.get("setup_ksm") == "yes":
         try:
             ksm = test_setup.KSMConfig(params, env)

virttest/test_setup/memory.py

@@ -34,3 +34,15 @@ def cleanup(self):
             if post_hugepages_surp > self._pre_hugepages_surp:
                 leak_num = post_hugepages_surp - self._pre_hugepages_surp
                 raise test_setup.HugePagesLeakError("%d huge pages leaked!" % leak_num)
+
+
+class TransparentHugePagesSetup(Setuper):
+    def setup(self):
+        if self.params.get("setup_thp") == "yes":
+            thp = test_setup.TransparentHugePageConfig(self.test, self.params, self.env)
+            thp.setup()
+
+    def cleanup(self):
+        if self.params.get("setup_thp") == "yes":
+            thp = test_setup.TransparentHugePageConfig(self.test, self.params, self.env)
+            thp.cleanup()