Comment 9 for bug 1762491

Sorry for going AWOL on you. Yes, the fix in 5.1.38-dfsg-0ubuntu1.16.04.1 from https://launchpad.net/~costamagnagianfranco/+archive/ubuntu/locutusofborg-ppa/+packages produces an OVA that works and has accelerated graphics in both VMware and VirtualBox.

One other thought in looking at how you fixed this: the notify-send "VBoxClient: the VirtualBox kernel service is not running. Exiting." is a bit distracting in VMware. I see in in looking at your updated /etc/init.d/virtualbox-guest-utils that you have an in_virtual_machine function to test if it's VirtualBox at all before probing for any kernel services. Something similar would be welcome in /etc/X11/Xsession.d/98vboxadd-xclient, perhaps:

--- /etc/X11/Xsession.d/98vboxadd-xclient
+++ 98vboxadd-xclient
@@ -15,6 +15,17 @@
 # hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 #

+in_virtual_machine()
+{
+ if [ -z "$(lspci -d 80ee:beef)" ]; then
+ echo "VirtualBox Additions disabled, not in a Virtual Machine" >&2
+ return 1
+ fi
+
+ return 0
+}
+in_virtual_machine || return
+
 # Sanity check: if non-writeable PID-files are present in the user home
 # directory VBoxClient will fail to start.
 for i in $HOME/.vboxclient-*.pid; do