vm-under-test: Set CPU/tuned configurations

The tuned-adm command needs a reboot in order to take effect.
In order to reboot during the virt-builder operation - the command
is done in a first-boot script.

Signed-off-by: Ram Lavi <ralavi@redhat.com>

vms/vm-under-test/scripts/build-vm-image

@@ -24,5 +24,6 @@ virt-builder centosstream-8 \
   --root-password password:redhat \
   --install cloud-init,kernel-rt,tuned,rt-tests \
   --run /root/scripts/customize-vm \
+  --firstboot /root/scripts/first-boot \
   --selinux-relabel \
   --output /output/kubevirt-realtime-checkup-vm.qcow2

vms/vm-under-test/scripts/first-boot

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+#
+# This file is part of the kiagnose project
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+# Copyright 2023 Red Hat, Inc.
+#
+
+set -e
+
+echo isolated_cores=1-2 >> /etc/tuned/realtime-virtual-guest-variables.conf
+echo isolate_managed_irq=Y >> /etc/tuned/realtime-virtual-guest-variables.conf
+tuned-adm profile realtime-virtual-guest
+
+reboot