Merge remote-tracking branch 'remotes/vivier2/tags/trivial-branch-for-6.2-pull-reques...
[qemu.git] / softmmu / rtc.c
1 /*
2 * RTC configuration and clock read
3 *
4 * Copyright (c) 2003-2020 QEMU contributors
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24
25 #include "qemu/osdep.h"
26 #include "qemu-common.h"
27 #include "qemu/cutils.h"
28 #include "qapi/error.h"
29 #include "qapi/qmp/qerror.h"
30 #include "qemu/error-report.h"
31 #include "qemu/option.h"
32 #include "qemu/timer.h"
33 #include "qom/object.h"
34 #include "sysemu/replay.h"
35 #include "sysemu/sysemu.h"
36
37 static enum {
38 RTC_BASE_UTC,
39 RTC_BASE_LOCALTIME,
40 RTC_BASE_DATETIME,
41 } rtc_base_type = RTC_BASE_UTC;
42 static time_t rtc_ref_start_datetime;
43 static int rtc_realtime_clock_offset; /* used only with QEMU_CLOCK_REALTIME */
44 static int rtc_host_datetime_offset = -1; /* valid & used only with
45 RTC_BASE_DATETIME */
46 QEMUClockType rtc_clock;
47 /***********************************************************/
48 /* RTC reference time/date access */
49 static time_t qemu_ref_timedate(QEMUClockType clock)
50 {
51 time_t value = qemu_clock_get_ms(clock) / 1000;
52 switch (clock) {
53 case QEMU_CLOCK_REALTIME:
54 value -= rtc_realtime_clock_offset;
55 /* fall through */
56 case QEMU_CLOCK_VIRTUAL:
57 value += rtc_ref_start_datetime;
58 break;
59 case QEMU_CLOCK_HOST:
60 if (rtc_base_type == RTC_BASE_DATETIME) {
61 value -= rtc_host_datetime_offset;
62 }
63 break;
64 default:
65 assert(0);
66 }
67 return value;
68 }
69
70 void qemu_get_timedate(struct tm *tm, int offset)
71 {
72 time_t ti = qemu_ref_timedate(rtc_clock);
73
74 ti += offset;
75
76 switch (rtc_base_type) {
77 case RTC_BASE_DATETIME:
78 case RTC_BASE_UTC:
79 gmtime_r(&ti, tm);
80 break;
81 case RTC_BASE_LOCALTIME:
82 localtime_r(&ti, tm);
83 break;
84 }
85 }
86
87 int qemu_timedate_diff(struct tm *tm)
88 {
89 time_t seconds;
90
91 switch (rtc_base_type) {
92 case RTC_BASE_DATETIME:
93 case RTC_BASE_UTC:
94 seconds = mktimegm(tm);
95 break;
96 case RTC_BASE_LOCALTIME:
97 {
98 struct tm tmp = *tm;
99 tmp.tm_isdst = -1; /* use timezone to figure it out */
100 seconds = mktime(&tmp);
101 break;
102 }
103 default:
104 abort();
105 }
106
107 return seconds - qemu_ref_timedate(QEMU_CLOCK_HOST);
108 }
109
110 static void configure_rtc_base_datetime(const char *startdate)
111 {
112 time_t rtc_start_datetime;
113 struct tm tm;
114
115 if (sscanf(startdate, "%d-%d-%dT%d:%d:%d", &tm.tm_year, &tm.tm_mon,
116 &tm.tm_mday, &tm.tm_hour, &tm.tm_min, &tm.tm_sec) == 6) {
117 /* OK */
118 } else if (sscanf(startdate, "%d-%d-%d",
119 &tm.tm_year, &tm.tm_mon, &tm.tm_mday) == 3) {
120 tm.tm_hour = 0;
121 tm.tm_min = 0;
122 tm.tm_sec = 0;
123 } else {
124 goto date_fail;
125 }
126 tm.tm_year -= 1900;
127 tm.tm_mon--;
128 rtc_start_datetime = mktimegm(&tm);
129 if (rtc_start_datetime == -1) {
130 date_fail:
131 error_report("invalid datetime format");
132 error_printf("valid formats: "
133 "'2006-06-17T16:01:21' or '2006-06-17'\n");
134 exit(1);
135 }
136 rtc_host_datetime_offset = rtc_ref_start_datetime - rtc_start_datetime;
137 rtc_ref_start_datetime = rtc_start_datetime;
138 }
139
140 void configure_rtc(QemuOpts *opts)
141 {
142 const char *value;
143
144 /* Set defaults */
145 rtc_clock = QEMU_CLOCK_HOST;
146 rtc_ref_start_datetime = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000;
147 rtc_realtime_clock_offset = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000;
148
149 value = qemu_opt_get(opts, "base");
150 if (value) {
151 if (!strcmp(value, "utc")) {
152 rtc_base_type = RTC_BASE_UTC;
153 } else if (!strcmp(value, "localtime")) {
154 Error *blocker = NULL;
155 rtc_base_type = RTC_BASE_LOCALTIME;
156 error_setg(&blocker, QERR_REPLAY_NOT_SUPPORTED,
157 "-rtc base=localtime");
158 replay_add_blocker(blocker);
159 } else {
160 rtc_base_type = RTC_BASE_DATETIME;
161 configure_rtc_base_datetime(value);
162 }
163 }
164 value = qemu_opt_get(opts, "clock");
165 if (value) {
166 if (!strcmp(value, "host")) {
167 rtc_clock = QEMU_CLOCK_HOST;
168 } else if (!strcmp(value, "rt")) {
169 rtc_clock = QEMU_CLOCK_REALTIME;
170 } else if (!strcmp(value, "vm")) {
171 rtc_clock = QEMU_CLOCK_VIRTUAL;
172 } else {
173 error_report("invalid option value '%s'", value);
174 exit(1);
175 }
176 }
177 value = qemu_opt_get(opts, "driftfix");
178 if (value) {
179 if (!strcmp(value, "slew")) {
180 object_register_sugar_prop("mc146818rtc",
181 "lost_tick_policy",
182 "slew",
183 false);
184 } else if (!strcmp(value, "none")) {
185 /* discard is default */
186 } else {
187 error_report("invalid option value '%s'", value);
188 exit(1);
189 }
190 }
191 }