xen_send_ipi
xen_send_ipi(ci, XEN_IPI_KPREEMPT);
int xen_send_ipi(struct cpu_info *, uint32_t);
(void)xen_send_ipi(ci, XEN_IPI_AST);
if (xen_send_ipi(ci, XEN_IPI_HVCB)) {
if (0 != xen_send_ipi(ci, ipimask)) {
if (0 != xen_send_ipi(ci, XEN_IPI_XCALL)) {
if (0 != xen_send_ipi(ci, XEN_IPI_GENERIC)) {