Intel 253666-024US - Manual (Page 760)

3-714 Vol. 2A MWAIT—Monitor Wait
INSTRUCTION SET REFERENCE, A-M
Compatibility Mode Exceptions
Same exceptions as in protected mode.
64-Bit Mode Exceptions
#GP(0) If the linear address of the operand in the CS, DS, ES, FS, or GS
segment is in a non-canonical form.
If RCX ≠ 0.
#SS(0) If the linear address of the operand in the SS segment is in a
non-canonical form.
#PF(fault-code) For a page fault.
#UD If the current privilege level is not 0.
If CPUID.01H:ECX.MONITOR[bit 3] = 0.