For the case CPU logic index is 0, RSP points to the very top of all AP stacks. That address is not mapped in page table. Cc: Guo Dong <guo.dong@intel.com> Cc: Ray Ni <ray.ni@intel.com> Cc: Sean Rhodes <sean@starlabs.systems> Cc: James Lu <james.lu@intel.com> Cc: Gua Guo <gua.guo@intel.com> Signed-off-by: Ted Kuo <ted.kuo@intel.com> Reviewed-by: Ray Ni <ray.ni@intel.com>