util: Enable KVM on VMs and ensure working in Runners

This patch:

1. Adds setup scripting to "provision_root.sh" to setup and enable KVM,
   for the 'vagrant' user, for VMs which are capable of this.
2. Runs a check on each VM to see if KVM can be run sucessfully within a
   docker container. If so, the GitHub Actions runner is given a 'kvm'
   label. It is unknown at this time if GitHub Runners can utlized KVM
   but it is open to their processes.

Change-Id: Idfcbb7bfa3e5b7cc47d29aea50fb1ebcafdb7acc

util/github-runners-vagrant/Vagrantfile

@@ -58,8 +58,32 @@ Vagrant.configure("2") do |config|
       # Copy the "action-run.sh" script from the host to the VM.
       runner.vm.provision "file", source: "./action-run.sh", destination: "/tmp/action-run.sh"
       runner.vm.provision :shell, privileged: false,  inline: "cp /tmp/action-run.sh ."
-      # Execute the actions-run.sh script on every boot. This configures the and starts the runner.
-      runner.vm.provision :shell, privileged: false, run: 'always', inline: "./action-run.sh #{PERSONAL_ACCESS_TOKEN} #{GITHUB_ORG} >> action-run.log 2>&1 &"
+
+      # The following attempts to see if KVM can be used inside the docker
+      # container.
+      #
+      # Almost all github action jobs run within a docker container. Therefore
+      # to be compatible with KVM, KVM must be enabled inside the docker.
+      #
+      # We used existence of "kvm-works" in the VM home directory is how we
+      # indicate that KVM is working. It is created if the 'kvm-ok' command is
+      # successful. This is then passed to the action-run.sh script to indicate
+      # that the runner can be used for KVM via the `kvm` label.
+      runner.vm.provision :shell, privileged: false, run: 'always',  inline: <<-SHELL
+           rm -f kvm-works
+           docker run --device /dev/kvm -v$(pwd):/work -w /work --rm ubuntu:22.04 bash -c "apt update -y && apt install -y cpu-checker && kvm-ok"
+           status=$?
+           if [[ ${status} == 0 ]]; then
+                echo >&1 "Success. KVM enabled."
+                echo "success" > kvm-works
+           else
+                echo >&2 "Failure. KVM not enabled."
+           fi
+           exit 0
+      SHELL
+      # Execute the actions-run.sh script on every boot. This configures and starts the runner.
+      # Note the 'kvm' label is applied to this runner if the "kvm-works" file eixsts. See above.
+      runner.vm.provision :shell, privileged: false, run: 'always', inline: "./action-run.sh #{PERSONAL_ACCESS_TOKEN} #{GITHUB_ORG} $(if [ -f 'kvm-works' ]; then echo 'kvm'; fi) >> action-run.log 2>&1 &"
     end
   end
 end

util/github-runners-vagrant/provision_root.sh

@@ -56,7 +56,8 @@ apt-get install -y \
   apt-transport-https ca-certificates \
   curl \
   gnupg \
-  lsb-release
+  lsb-release \
+  cpu-checker
 
 # Install docker
 apt-get install -y apt-transport-https ca-certificates curl gnupg lsb-release
@@ -70,6 +71,22 @@ apt-get install -y docker-ce docker-ce-cli containerd.io
 # work.
 usermod -aG docker vagrant
 
+kvm-ok
+kvm_ok_status=$?
+
+# `kvm-ok` will return a exit zero if the machine supports KVM, and non-zero
+# otherwise. If the machine support KVM, let's enable it.
+if [[ ${kvm_ok_status} == 0 ]]; then
+    apt install -y qemu-kvm \
+                   virt-manager \
+                  libvirt-daemon-system virtinst \
+                  libvirt-clients bridge-utils && \
+    sudo systemctl enable --now libvirtd && \
+    sudo systemctl start libvirtd && \
+    usermod -aG kvm vagrant && \
+    usermod -aG libvirt vagrant
+fi
+
 # Cleanup
 apt-get autoremove -y