NLDT
NLDT * sizeof(ldtstore[0]) - 1, SDT_SYSLDT, SEL_KPL, 0, 0);
const size_t min_ldt_size = NLDT * sizeof(union descriptor);
nldt = NLDT;
const size_t min_ldt_size = NLDT * sizeof(union descriptor);
initctx->ldt_ents = NLDT;
xen_set_ldt((vaddr_t)ldtstore, NLDT);