hyperv_hypercall
__weak_alias(hyperv_hypercall, hyperv_hypercall_error);
return hyperv_hypercall(HYPERCALL_POST_MESSAGE, msg, 0);
return hyperv_hypercall(HYPERCALL_SIGNAL_EVENT, monprm, 0);
uint64_t hyperv_hypercall(uint64_t, paddr_t, paddr_t);