VCPUOP_is_up
is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up,
while (HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu), NULL)) {
if (HYPERVISOR_vcpu_op(VCPUOP_is_up, cpus, NULL) < 0)