For Nova under VirtualBox I get that error

[Paul Dufresne]

Well,I never got understanding clearly these SYSENTER/SYSEXIT instructions.
Trying to google it a bit, I find this that seems to make some kind of
sense (but not too much honestly).
Basically, someone in similar situation was told it need to save MSR
(most particularly IA32_STAR MSR),
for using SYSENTER/SYSEXIT correctly:
https://software.intel.com/en-us/forums/virtualization-software-development/topic/278918

Also about SysExit and link to MSR: http://wiki.osdev.org/SYSENTER