HYPERVISOR_stack_switch
HYPERVISOR_stack_switch(GSEL(GDATA_SEL, SEL_KPL), new->pcb_rsp0);
HYPERVISOR_stack_switch(GSEL(GDATA_SEL, SEL_KPL), pcb->pcb_rsp0);
HYPERVISOR_stack_switch(GSEL(GDATA_SEL, SEL_KPL), pcb->pcb_esp0);
HYPERVISOR_stack_switch(GSEL(GDATA_SEL, SEL_KPL), pcb->pcb_esp0);