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/cutils.h" 27 #include "qapi/error.h" 28 #include "qemu/error-report.h" 29 #include "qemu/option.h" 30 #include "qemu/timer.h" 31 #include "qom/object.h" 32 #include "sysemu/replay.h" 33 #include "sysemu/sysemu.h" 34 #include "sysemu/rtc.h" 35 #include "hw/rtc/mc146818rtc.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 g_assert_not_reached(); 66 } 67 return value; 68 } 69 70 void qemu_get_timedate(struct tm *tm, time_t 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 time_t 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 rtc_base_type = RTC_BASE_LOCALTIME; 155 replay_add_blocker("-rtc base=localtime"); 156 } else { 157 rtc_base_type = RTC_BASE_DATETIME; 158 configure_rtc_base_datetime(value); 159 } 160 } 161 value = qemu_opt_get(opts, "clock"); 162 if (value) { 163 if (!strcmp(value, "host")) { 164 rtc_clock = QEMU_CLOCK_HOST; 165 } else if (!strcmp(value, "rt")) { 166 rtc_clock = QEMU_CLOCK_REALTIME; 167 } else if (!strcmp(value, "vm")) { 168 rtc_clock = QEMU_CLOCK_VIRTUAL; 169 } else { 170 error_report("invalid option value '%s'", value); 171 exit(1); 172 } 173 } 174 value = qemu_opt_get(opts, "driftfix"); 175 if (value) { 176 if (!strcmp(value, "slew")) { 177 object_register_sugar_prop(TYPE_MC146818_RTC, 178 "lost_tick_policy", 179 "slew", 180 false); 181 if (!object_class_by_name(TYPE_MC146818_RTC)) { 182 warn_report("driftfix 'slew' is not available with this machine"); 183 } 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 } 192