summaryrefslogtreecommitdiffstats
path: root/softmmu/rtc.c
blob: 5632684fc9d5bbc51507b5a89d03ce4ee208adcf (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
/*
 * RTC configuration and clock read
 *
 * Copyright (c) 2003-2020 QEMU contributors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "qemu/osdep.h"
#include "qemu-common.h"
#include "qemu/cutils.h"
#include "qapi/error.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.h"
#include "qemu/option.h"
#include "qemu/timer.h"
#include "qom/object.h"
#include "sysemu/replay.h"
#include "sysemu/sysemu.h"

static enum {
    RTC_BASE_UTC,
    RTC_BASE_LOCALTIME,
    RTC_BASE_DATETIME,
} rtc_base_type = RTC_BASE_UTC;
static time_t rtc_ref_start_datetime;
static int rtc_realtime_clock_offset; /* used only with QEMU_CLOCK_REALTIME */
static int rtc_host_datetime_offset = -1; /* valid & used only with
                                             RTC_BASE_DATETIME */
QEMUClockType rtc_clock;
/***********************************************************/
/* RTC reference time/date access */
static time_t qemu_ref_timedate(QEMUClockType clock)
{
    time_t value = qemu_clock_get_ms(clock) / 1000;
    switch (clock) {
    case QEMU_CLOCK_REALTIME:
        value -= rtc_realtime_clock_offset;
        /* fall through */
    case QEMU_CLOCK_VIRTUAL:
        value += rtc_ref_start_datetime;
        break;
    case QEMU_CLOCK_HOST:
        if (rtc_base_type == RTC_BASE_DATETIME) {
            value -= rtc_host_datetime_offset;
        }
        break;
    default:
        assert(0);
    }
    return value;
}

void qemu_get_timedate(struct tm *tm, int offset)
{
    time_t ti = qemu_ref_timedate(rtc_clock);

    ti += offset;

    switch (rtc_base_type) {
    case RTC_BASE_DATETIME:
    case RTC_BASE_UTC:
        gmtime_r(&ti, tm);
        break;
    case RTC_BASE_LOCALTIME:
        localtime_r(&ti, tm);
        break;
    }
}

int qemu_timedate_diff(struct tm *tm)
{
    time_t seconds;

    switch (rtc_base_type) {
    case RTC_BASE_DATETIME:
    case RTC_BASE_UTC:
        seconds = mktimegm(tm);
        break;
    case RTC_BASE_LOCALTIME:
    {
        struct tm tmp = *tm;
        tmp.tm_isdst = -1; /* use timezone to figure it out */
        seconds = mktime(&tmp);
        break;
    }
    default:
        abort();
    }

    return seconds - qemu_ref_timedate(QEMU_CLOCK_HOST);
}

static void configure_rtc_base_datetime(const char *startdate)
{
    time_t rtc_start_datetime;
    struct tm tm;

    if (sscanf(startdate, "%d-%d-%dT%d:%d:%d", &tm.tm_year, &tm.tm_mon,
               &tm.tm_mday, &tm.tm_hour, &tm.tm_min, &tm.tm_sec) == 6) {
        /* OK */
    } else if (sscanf(startdate, "%d-%d-%d",
                      &tm.tm_year, &tm.tm_mon, &tm.tm_mday) == 3) {
        tm.tm_hour = 0;
        tm.tm_min = 0;
        tm.tm_sec = 0;
    } else {
        goto date_fail;
    }
    tm.tm_year -= 1900;
    tm.tm_mon--;
    rtc_start_datetime = mktimegm(&tm);
    if (rtc_start_datetime == -1) {
    date_fail:
        error_report("invalid datetime format");
        error_printf("valid formats: "
                     "'2006-06-17T16:01:21' or '2006-06-17'\n");
        exit(1);
    }
    rtc_host_datetime_offset = rtc_ref_start_datetime - rtc_start_datetime;
    rtc_ref_start_datetime = rtc_start_datetime;
}

void configure_rtc(QemuOpts *opts)
{
    const char *value;

    /* Set defaults */
    rtc_clock = QEMU_CLOCK_HOST;
    rtc_ref_start_datetime = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
    rtc_realtime_clock_offset = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;

    value = qemu_opt_get(opts, "base");
    if (value) {
        if (!strcmp(value, "utc")) {
            rtc_base_type = RTC_BASE_UTC;
        } else if (!strcmp(value, "localtime")) {
            Error *blocker = NULL;
            rtc_base_type = RTC_BASE_LOCALTIME;
            error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED,
                      "-rtc base=localtime");
            replay_add_blocker(blocker);
        } else {
            rtc_base_type = RTC_BASE_DATETIME;
            configure_rtc_base_datetime(value);
        }
    }
    value = qemu_opt_get(opts, "clock");
    if (value) {
        if (!strcmp(value, "host")) {
            rtc_clock = QEMU_CLOCK_HOST;
        } else if (!strcmp(value, "rt")) {
            rtc_clock = QEMU_CLOCK_REALTIME;
        } else if (!strcmp(value, "vm")) {
            rtc_clock = QEMU_CLOCK_VIRTUAL;
        } else {
            error_report("invalid option value '%s'", value);
            exit(1);
        }
    }
    value = qemu_opt_get(opts, "driftfix");
    if (value) {
        if (!strcmp(value, "slew")) {
            object_register_sugar_prop("mc146818rtc",
                                       "lost_tick_policy",
                                       "slew",
                                       false);
        } else if (!strcmp(value, "none")) {
            /* discard is default */
        } else {
            error_report("invalid option value '%s'", value);
            exit(1);
        }
    }
}