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 "qapi/qmp/qerror.h" 29 #include "qemu/error-report.h" 30 #include "qemu/option.h" 31 #include "qemu/timer.h" 32 #include "qom/object.h" 33 #include "sysemu/replay.h" 34 #include "sysemu/sysemu.h" 35 #include "sysemu/rtc.h" 36 #include "hw/rtc/mc146818rtc.h" 37 38 static enum { 39 RTC_BASE_UTC, 40 RTC_BASE_LOCALTIME, 41 RTC_BASE_DATETIME, 42 } rtc_base_type = RTC_BASE_UTC; 43 static time_t rtc_ref_start_datetime; 44 static int rtc_realtime_clock_offset; /* used only with QEMU_CLOCK_REALTIME */ 45 static int rtc_host_datetime_offset = -1; /* valid & used only with 46 RTC_BASE_DATETIME */ 47 QEMUClockType rtc_clock; 48 /***********************************************************/ 49 /* RTC reference time/date access */ 50 static time_t qemu_ref_timedate(QEMUClockType clock) 51 { 52 time_t value = qemu_clock_get_ms(clock) / 1000; 53 switch (clock) { 54 case QEMU_CLOCK_REALTIME: 55 value -= rtc_realtime_clock_offset; 56 /* fall through */ 57 case QEMU_CLOCK_VIRTUAL: 58 value += rtc_ref_start_datetime; 59 break; 60 case QEMU_CLOCK_HOST: 61 if (rtc_base_type == RTC_BASE_DATETIME) { 62 value -= rtc_host_datetime_offset; 63 } 64 break; 65 default: 66 assert(0); 67 } 68 return value; 69 } 70 71 void qemu_get_timedate(struct tm *tm, time_t offset) 72 { 73 time_t ti = qemu_ref_timedate(rtc_clock); 74 75 ti += offset; 76 77 switch (rtc_base_type) { 78 case RTC_BASE_DATETIME: 79 case RTC_BASE_UTC: 80 gmtime_r(&ti, tm); 81 break; 82 case RTC_BASE_LOCALTIME: 83 localtime_r(&ti, tm); 84 break; 85 } 86 } 87 88 time_t qemu_timedate_diff(struct tm *tm) 89 { 90 time_t seconds; 91 92 switch (rtc_base_type) { 93 case RTC_BASE_DATETIME: 94 case RTC_BASE_UTC: 95 seconds = mktimegm(tm); 96 break; 97 case RTC_BASE_LOCALTIME: 98 { 99 struct tm tmp = *tm; 100 tmp.tm_isdst = -1; /* use timezone to figure it out */ 101 seconds = mktime(&tmp); 102 break; 103 } 104 default: 105 abort(); 106 } 107 108 return seconds - qemu_ref_timedate(QEMU_CLOCK_HOST); 109 } 110 111 static void configure_rtc_base_datetime(const char *startdate) 112 { 113 time_t rtc_start_datetime; 114 struct tm tm; 115 116 if (sscanf(startdate, "%d-%d-%dT%d:%d:%d", &tm.tm_year, &tm.tm_mon, 117 &tm.tm_mday, &tm.tm_hour, &tm.tm_min, &tm.tm_sec) == 6) { 118 /* OK */ 119 } else if (sscanf(startdate, "%d-%d-%d", 120 &tm.tm_year, &tm.tm_mon, &tm.tm_mday) == 3) { 121 tm.tm_hour = 0; 122 tm.tm_min = 0; 123 tm.tm_sec = 0; 124 } else { 125 goto date_fail; 126 } 127 tm.tm_year -= 1900; 128 tm.tm_mon--; 129 rtc_start_datetime = mktimegm(&tm); 130 if (rtc_start_datetime == -1) { 131 date_fail: 132 error_report("invalid datetime format"); 133 error_printf("valid formats: " 134 "'2006-06-17T16:01:21' or '2006-06-17'\n"); 135 exit(1); 136 } 137 rtc_host_datetime_offset = rtc_ref_start_datetime - rtc_start_datetime; 138 rtc_ref_start_datetime = rtc_start_datetime; 139 } 140 141 void configure_rtc(QemuOpts *opts) 142 { 143 const char *value; 144 145 /* Set defaults */ 146 rtc_clock = QEMU_CLOCK_HOST; 147 rtc_ref_start_datetime = qemu_clock_get_ms(QEMU_CLOCK_HOST) / 1000; 148 rtc_realtime_clock_offset = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) / 1000; 149 150 value = qemu_opt_get(opts, "base"); 151 if (value) { 152 if (!strcmp(value, "utc")) { 153 rtc_base_type = RTC_BASE_UTC; 154 } else if (!strcmp(value, "localtime")) { 155 rtc_base_type = RTC_BASE_LOCALTIME; 156 replay_add_blocker("-rtc base=localtime"); 157 } else { 158 rtc_base_type = RTC_BASE_DATETIME; 159 configure_rtc_base_datetime(value); 160 } 161 } 162 value = qemu_opt_get(opts, "clock"); 163 if (value) { 164 if (!strcmp(value, "host")) { 165 rtc_clock = QEMU_CLOCK_HOST; 166 } else if (!strcmp(value, "rt")) { 167 rtc_clock = QEMU_CLOCK_REALTIME; 168 } else if (!strcmp(value, "vm")) { 169 rtc_clock = QEMU_CLOCK_VIRTUAL; 170 } else { 171 error_report("invalid option value '%s'", value); 172 exit(1); 173 } 174 } 175 value = qemu_opt_get(opts, "driftfix"); 176 if (value) { 177 if (!strcmp(value, "slew")) { 178 object_register_sugar_prop(TYPE_MC146818_RTC, 179 "lost_tick_policy", 180 "slew", 181 false); 182 if (!object_class_by_name(TYPE_MC146818_RTC)) { 183 warn_report("driftfix 'slew' is not available with this machine"); 184 } 185 } else if (!strcmp(value, "none")) { 186 /* discard is default */ 187 } else { 188 error_report("invalid option value '%s'", value); 189 exit(1); 190 } 191 } 192 } 193