env_process: Refactor QEMU coverage report resetter

Refactor the piece of code in env_process.preprocess that resetted gcov
before running tests or creating VMs. Don't merge it with the
postprocess step related to gcov as well, as it would break the order
(relative to the process() call) in which they are run.

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

virttest/env_process.py

@@ -45,6 +45,7 @@
 # lazy imports for dependencies that are not needed in all modes of use
 from virttest._wrappers import lazy_import
 from virttest.test_setup.core import SetupManager
+from virttest.test_setup.gcov import ResetQemuGCov
 from virttest.test_setup.libvirt_setup import LibvirtdDebugLogConfig
 from virttest.test_setup.migration import MigrationEnvSetup
 from virttest.test_setup.networking import (
@@ -1014,24 +1015,8 @@ def preprocess(test, params, env):
         vms = list(set(params.objects("vms") + migrate_vms))
         params["vms"] = " ".join(vms)
 
-    # Check if code coverage for qemu is enabled and
-    # if coverage reset is enabled too, reset coverage report
-    gcov_qemu = params.get("gcov_qemu", "no") == "yes"
-    gcov_qemu_reset = params.get("gcov_qemu_reset", "no") == "yes"
-    if gcov_qemu and gcov_qemu_reset:
-        qemu_builddir = os.path.join(test.bindir, "build", "qemu")
-        qemu_bin = os.path.join(test.bindir, "bin", "qemu")
-        if os.path.isdir(qemu_builddir) and os.path.isfile(qemu_bin):
-            os.chdir(qemu_builddir)
-            # Looks like libvirt process does not have permissions to write to
-            # coverage files, hence give write for all files in qemu source
-            reset_cmd = "make clean-coverage;%s -version;" % qemu_bin
-            reset_cmd += (
-                'find %s -name "*.gcda" -exec chmod a=rwx {} \;' % qemu_builddir
-            )
-            a_process.system(reset_cmd, shell=True)
-
     _setup_manager.initialize(test, params, env)
+    _setup_manager.register(ResetQemuGCov)
     _setup_manager.register(VerifyHostDMesg)
     _setup_manager.register(SwitchSMTOff)
     _setup_manager.register(CheckRunningAsRoot)

virttest/test_setup/gcov.py

@@ -0,0 +1,28 @@
+import os
+
+from avocado.utils import process as a_process
+
+from virttest.test_setup.core import Setuper
+
+
+class ResetQemuGCov(Setuper):
+    def setup(self):
+        # Check if code coverage for qemu is enabled and
+        # if coverage reset is enabled too, reset coverage report
+        gcov_qemu = self.params.get("gcov_qemu", "no") == "yes"
+        gcov_qemu_reset = self.params.get("gcov_qemu_reset", "no") == "yes"
+        if gcov_qemu and gcov_qemu_reset:
+            qemu_builddir = os.path.join(self.test.bindir, "build", "qemu")
+            qemu_bin = os.path.join(self.test.bindir, "bin", "qemu")
+            if os.path.isdir(qemu_builddir) and os.path.isfile(qemu_bin):
+                os.chdir(qemu_builddir)
+                # Looks like libvirt process does not have permissions to write to
+                # coverage files, hence give write for all files in qemu source
+                reset_cmd = "make clean-coverage;%s -version;" % qemu_bin
+                reset_cmd += (
+                    'find %s -name "*.gcda" -exec chmod a=rwx {} \;' % qemu_builddir
+                )
+                a_process.system(reset_cmd, shell=True)
+
+    def cleanup(self):
+        pass