Currently, the vmxon region isn't used in the nested case.
However, according to the spec, the vmxon instruction performs
additional sanity checks on this region and the associated
pointer. Modify emulated vmxon to better adhere to the spec
requirements
Signed-off-by: NBandan Das <bsd@redhat.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>