VCPUOP_is_up
if (HYPERVISOR_vcpu_op(VCPUOP_is_up, id, NULL) == 0)
switch (-HYPERVISOR_vcpu_op(VCPUOP_is_up, id, NULL)) {
if (HYPERVISOR_vcpu_op(VCPUOP_is_up, cp->cpu_id, NULL) != 0) {
if (HYPERVISOR_vcpu_op(VCPUOP_is_up, id, NULL) < 0)