19 Sep
2016
19 Sep
'16
12:38 a.m.
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/...
Also about SysExit and link to MSR: http://wiki.osdev.org/SYSENTER