Symbol: HYPERVISOR_callback_op
usr/src/uts/i86xpv/os/xen_machdep.c
265
if (HYPERVISOR_callback_op(CALLBACKOP_register, &cb) != 0 &&
usr/src/uts/intel/sys/hypervisor.h
240
extern long HYPERVISOR_callback_op(int, void *);