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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 "system/kvm.h"
17 #include "system/tcg.h"
18 #include "system/qtest.h"
19 #include "migration/qemu-file-types.h"
20 #include "migration/register.h"
21
22 void s390_init_tod(void)
23 {
24 Object *obj;
25
26 if (kvm_enabled()) {
27 obj = object_new(TYPE_KVM_S390_TOD);
28 } else if (tcg_enabled()) {
29 obj = object_new(TYPE_QEMU_S390_TOD);
30 } else if (qtest_enabled()) {
31 return;
32 } else {
33 error_report("current accelerator not handled in s390_init_tod!");
34 abort();
35 }
36 object_property_add_child(qdev_get_machine(), TYPE_S390_TOD, obj);
37 object_unref(obj);
38
39 qdev_realize(DEVICE(obj), NULL, &error_fatal);
40 }
41
42 S390TODState *s390_get_todstate(void)
43 {
44 static S390TODState *ts;
45
46 if (!ts) {
47 ts = S390_TOD(object_resolve_path_type("", TYPE_S390_TOD, NULL));
48 }
49
50 return ts;
51 }
52
53 #define S390_TOD_CLOCK_VALUE_MISSING 0x00
54 #define S390_TOD_CLOCK_VALUE_PRESENT 0x01
55
56 static void s390_tod_save(QEMUFile *f, void *opaque)
57 {
58 S390TODState *td = opaque;
59 S390TODClass *tdc = S390_TOD_GET_CLASS(td);
60 Error *err = NULL;
61 S390TOD tod;
62
63 tdc->get(td, &tod, &err);
64 if (err) {
65 warn_report_err(err);
66 error_printf("Guest clock will not be migrated "
67 "which could cause the guest to hang.");
68 qemu_put_byte(f, S390_TOD_CLOCK_VALUE_MISSING);
69 return;
70 }
71
72 qemu_put_byte(f, S390_TOD_CLOCK_VALUE_PRESENT);
73 qemu_put_byte(f, tod.high);
74 qemu_put_be64(f, tod.low);
75
76 tdc->set(td, &tod, &err);
77 if (err) {
78 warn_report_err(err);
79 }
80 }
81
82 static int s390_tod_load(QEMUFile *f, void *opaque, int version_id)
83 {
84 S390TODState *td = opaque;
85 S390TODClass *tdc = S390_TOD_GET_CLASS(td);
86 Error *err = NULL;
87 S390TOD tod;
88
89 if (qemu_get_byte(f) == S390_TOD_CLOCK_VALUE_MISSING) {
90 warn_report("Guest clock was not migrated. This could "
91 "cause the guest to hang.");
92 return 0;
93 }
94
95 tod.high = qemu_get_byte(f);
96 tod.low = qemu_get_be64(f);
97
98 tdc->set(td, &tod, &err);
99 if (err) {
100 error_report_err(err);
101 return -1;
102 }
103 return 0;
104 }
105
106 static SaveVMHandlers savevm_tod = {
107 .save_state = s390_tod_save,
108 .load_state = s390_tod_load,
109 };
110
111 static void s390_tod_realize(DeviceState *dev, Error **errp)
112 {
113 S390TODState *td = S390_TOD(dev);
114
115 /* Legacy migration interface */
116 register_savevm_live("todclock", 0, 1, &savevm_tod, td);
117 }
118
119 static void s390_tod_class_init(ObjectClass *oc, const void *data)
120 {
121 DeviceClass *dc = DEVICE_CLASS(oc);
122
123 dc->desc = "TOD (Time Of Day) Clock";
124 dc->realize = s390_tod_realize;
125 set_bit(DEVICE_CATEGORY_MISC, dc->categories);
126
127 /* We only have one TOD clock in the system attached to the machine */
128 dc->user_creatable = false;
129 }
130
131 static const TypeInfo s390_tod_info = {
132 .name = TYPE_S390_TOD,
133 .parent = TYPE_DEVICE,
134 .instance_size = sizeof(S390TODState),
135 .class_init = s390_tod_class_init,
136 .class_size = sizeof(S390TODClass),
137 .abstract = true,
138 };
139
140 static void register_types(void)
141 {
142 type_register_static(&s390_tod_info);
143 }
144 type_init(register_types);