LXR qemu/hw/s390x/tod.c

   1/*
   2 * TOD (Time Of Day) clock
   3 *
   4 * Copyright 2018 Red Hat, Inc.
   5 * Author(s): David Hildenbrand <david@redhat.com>
   6 *
   7 * This work is licensed under the terms of the GNU GPL, version 2 or later.
   8 * See the COPYING file in the top-level directory.
   9 */
  10
  11#include "qemu/osdep.h"
  12#include "hw/s390x/tod.h"
  13#include "qapi/error.h"
  14#include "qemu/error-report.h"
  15#include "qemu/module.h"
  16#include "sysemu/kvm.h"
  17#include "migration/qemu-file-types.h"
  18#include "migration/register.h"
  19
  20void s390_init_tod(void)
  21{
  22    Object *obj;
  23
  24    if (kvm_enabled()) {
  25        obj = object_new(TYPE_KVM_S390_TOD);
  26    } else {
  27        obj = object_new(TYPE_QEMU_S390_TOD);
  28    }
  29    object_property_add_child(qdev_get_machine(), TYPE_S390_TOD, obj, NULL);
  30    object_unref(obj);
  31
  32    qdev_init_nofail(DEVICE(obj));
  33}
  34
  35S390TODState *s390_get_todstate(void)
  36{
  37    static S390TODState *ts;
  38
  39    if (!ts) {
  40        ts = S390_TOD(object_resolve_path_type("", TYPE_S390_TOD, NULL));
  41    }
  42
  43    return ts;
  44}
  45
  46#define S390_TOD_CLOCK_VALUE_MISSING    0x00
  47#define S390_TOD_CLOCK_VALUE_PRESENT    0x01
  48
  49static void s390_tod_save(QEMUFile *f, void *opaque)
  50{
  51    S390TODState *td = opaque;
  52    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
  53    Error *err = NULL;
  54    S390TOD tod;
  55
  56    tdc->get(td, &tod, &err);
  57    if (err) {
  58        warn_report_err(err);
  59        error_printf("Guest clock will not be migrated "
  60                     "which could cause the guest to hang.");
  61        qemu_put_byte(f, S390_TOD_CLOCK_VALUE_MISSING);
  62        return;
  63    }
  64
  65    qemu_put_byte(f, S390_TOD_CLOCK_VALUE_PRESENT);
  66    qemu_put_byte(f, tod.high);
  67    qemu_put_be64(f, tod.low);
  68}
  69
  70static int s390_tod_load(QEMUFile *f, void *opaque, int version_id)
  71{
  72    S390TODState *td = opaque;
  73    S390TODClass *tdc = S390_TOD_GET_CLASS(td);
  74    Error *err = NULL;
  75    S390TOD tod;
  76
  77    if (qemu_get_byte(f) == S390_TOD_CLOCK_VALUE_MISSING) {
  78        warn_report("Guest clock was not migrated. This could "
  79                    "cause the guest to hang.");
  80        return 0;
  81    }
  82
  83    tod.high = qemu_get_byte(f);
  84    tod.low = qemu_get_be64(f);
  85
  86    tdc->set(td, &tod, &err);
  87    if (err) {
  88        error_report_err(err);
  89        return -1;
  90    }
  91    return 0;
  92}
  93
  94static SaveVMHandlers savevm_tod = {
  95    .save_state = s390_tod_save,
  96    .load_state = s390_tod_load,
  97};
  98
  99static void s390_tod_realize(DeviceState *dev, Error **errp)
 100{
 101    S390TODState *td = S390_TOD(dev);
 102
 103    /* Legacy migration interface */
 104    register_savevm_live("todclock", 0, 1, &savevm_tod, td);
 105}
 106
 107static void s390_tod_class_init(ObjectClass *oc, void *data)
 108{
 109    DeviceClass *dc = DEVICE_CLASS(oc);
 110
 111    dc->desc = "TOD (Time Of Day) Clock";
 112    dc->realize = s390_tod_realize;
 113    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
 114
 115    /* We only have one TOD clock in the system attached to the machine */
 116    dc->user_creatable = false;
 117}
 118
 119static TypeInfo s390_tod_info = {
 120    .name = TYPE_S390_TOD,
 121    .parent = TYPE_DEVICE,
 122    .instance_size = sizeof(S390TODState),
 123    .class_init = s390_tod_class_init,
 124    .class_size = sizeof(S390TODClass),
 125    .abstract = true,
 126};
 127
 128static void register_types(void)
 129{
 130    type_register_static(&s390_tod_info);
 131}
 132type_init(register_types);
 133