xen_idt_write
xen_idt_write(idt, vec);
xen_idt_write(gate, vec);
xen_idt_write(&idt[brand_tbl[i].ih_inum],
xen_idt_write(&idt[brand_tbl[i].ih_inum],
xen_idt_write(&idt0[vec], vec);
extern void xen_idt_write(gate_desc_t *, uint_t);