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