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