set_ldt
set_ldt(NULL, 0);
PVOP_VCALL2(pv_ops, cpu.set_ldt, addr, entries);
void (*set_ldt)(const void *desc, unsigned entries);
set_ldt(ldt_slot_va(ldt->slot), ldt->nr_entries);
set_ldt(ldt->entries, ldt->nr_entries);
.cpu.set_ldt = native_set_ldt,
pv_ops.cpu.set_ldt = xen_set_ldt;