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
  18 void 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
  33 S390TODState *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
  47 static 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
  68 static 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
  92 static SaveVMHandlers savevm_tod = {
  93     .save_state = s390_tod_save,
  94     .load_state = s390_tod_load,
  95 };
  96
  97 static 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
 105 static 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
 117 static 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
 126 static void register_types(void)
 127 {
 128     type_register_static(&s390_tod_info);
 129 }
 130 type_init(register_types);