env_process: Refactor huge pages setup/cleanup steps

Creating a new Setuper subclass for setting and cleaning huge pages up.
Removing the original code from virttest.env_process and replacing it
instead with the new HugePagesSetup class being registered in the
setup_manager.

_pre_hugepages_surp and _post_hugepages_surp were left in env_process.
Their goal is to provide a mechanism in env_process to raise a TestFail
in case pages were leaked during a test. If that mechanism was
refactored into the setuper, the TestFail would be masked by just an
Error due to the way setup_manager handles postprocess exceptions.
Changing the way SetupManager handles that requires bigger discussion on
how the test infrastructure should handle test status reports, which is
a way broader topic that what this patch aims to be.

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 <[email protected]>

virttest/env_process.py

@@ -46,6 +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.migration import MigrationEnvSetup
 from virttest.test_setup.networking import (
     BridgeConfig,
@@ -1023,6 +1024,7 @@ def preprocess(test, params, env):
     _setup_manager.register(CheckVirtioWinVersion)
     _setup_manager.register(CheckLibvirtVersion)
     _setup_manager.register(LogVersionInfo)
+    _setup_manager.register(HugePagesSetup)
     _setup_manager.do_setup()
 
     vm_type = params.get("vm_type")
@@ -1031,24 +1033,6 @@ def preprocess(test, params, env):
 
     libvirtd_inst = None
 
-    # If guest is configured to be backed by hugepages, setup hugepages in host
-    if params.get("hugepage") == "yes":
-        params["setup_hugepages"] = "yes"
-
-    if params.get("setup_hugepages") == "yes":
-        global _pre_hugepages_surp
-        h = test_setup.HugePageConfig(params)
-        _pre_hugepages_surp = h.ext_hugepages_surp
-        suggest_mem = h.setup()
-        if suggest_mem is not None:
-            params["mem"] = suggest_mem
-        if not params.get("hugepage_path"):
-            params["hugepage_path"] = h.hugepage_path
-        if vm_type == "libvirt":
-            if libvirtd_inst is None:
-                libvirtd_inst = utils_libvirtd.Libvirtd()
-            libvirtd_inst.restart()
-
     if params.get("setup_thp") == "yes":
         thp = test_setup.TransparentHugePageConfig(test, params, env)
         thp.setup()
@@ -1534,21 +1518,6 @@ def postprocess(test, params, env):
     libvirtd_inst = None
     vm_type = params.get("vm_type")
 
-    if params.get("setup_hugepages") == "yes":
-        global _post_hugepages_surp
-        try:
-            h = test_setup.HugePageConfig(params)
-            h.cleanup()
-            if vm_type == "libvirt":
-                if libvirtd_inst is None:
-                    libvirtd_inst = utils_libvirtd.Libvirtd()
-                libvirtd_inst.restart()
-        except Exception as details:
-            err += "\nHP cleanup: %s" % str(details).replace("\\n", "\n  ")
-            LOG.error(details)
-        else:
-            _post_hugepages_surp = h.ext_hugepages_surp
-
     if params.get("setup_thp") == "yes":
         try:
             thp = test_setup.TransparentHugePageConfig(test, params, env)

virttest/test_setup/memory.py

@@ -0,0 +1,27 @@
+from virttest import env_process, test_setup, utils_libvirtd
+from virttest.test_setup.core import Setuper
+
+
+class HugePagesSetup(Setuper):
+    def setup(self):
+        # If guest is configured to be backed by hugepages, setup hugepages in host
+        if self.params.get("hugepage") == "yes":
+            self.params["setup_hugepages"] = "yes"
+        if self.params.get("setup_hugepages") == "yes":
+            h = test_setup.HugePageConfig(self.params)
+            env_process._pre_hugepages_surp = h.ext_hugepages_surp
+            suggest_mem = h.setup()
+            if suggest_mem is not None:
+                self.params["mem"] = suggest_mem
+            if not self.params.get("hugepage_path"):
+                self.params["hugepage_path"] = h.hugepage_path
+            if self.params.get("vm_type") == "libvirt":
+                utils_libvirtd.Libvirtd().restart()
+
+    def cleanup(self):
+        if self.params.get("setup_hugepages") == "yes":
+            h = test_setup.HugePageConfig(self.params)
+            h.cleanup()
+            if self.params.get("vm_type") == "libvirt":
+                utils_libvirtd.Libvirtd().restart()
+            env_process._post_hugepages_surp = h.ext_hugepages_surp