Refactor RTC command line switches

Deprecate -localtime, -setdate and -rtc-td-hack in favor of a new
unified command line switch:

    -rtc [base=utc|localtime|date][,driftfix=none|slew]

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

4 files changed, 119 insertions, 57 deletions

diff --git a/qemu-config.c b/qemu-config.c
index 555c7ba091..3dce91d80e 100644
--- a/qemu-config.c
+++ b/qemu-config.c
@@ -151,6 +151,23 @@ QemuOptsList qemu_device_opts = {
     },
 };
 
+QemuOptsList qemu_rtc_opts = {
+    .name = "rtc",
+    .head = QTAILQ_HEAD_INITIALIZER(qemu_rtc_opts.head),
+    .desc = {
+        {
+            .name = "base",
+            .type = QEMU_OPT_STRING,
+#ifdef TARGET_I386
+        },{
+            .name = "driftfix",
+            .type = QEMU_OPT_STRING,
+#endif
+        },
+        { /* end if list */ }
+    },
+};
+
 static QemuOptsList *lists[] = {
     &qemu_drive_opts,
     &qemu_chardev_opts,
diff --git a/qemu-config.h b/qemu-config.h
index 13b0f19304..4ae7b74fe1 100644
--- a/qemu-config.h
+++ b/qemu-config.h
@@ -4,6 +4,7 @@
 extern QemuOptsList qemu_drive_opts;
 extern QemuOptsList qemu_chardev_opts;
 extern QemuOptsList qemu_device_opts;
+extern QemuOptsList qemu_rtc_opts;
 
 int qemu_set_option(const char *str);
 
diff --git a/qemu-options.hx b/qemu-options.hx
index d3aa55b635..586474e39b 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -681,15 +681,9 @@ slows down the IDE transfers).
 ETEXI
 
 #ifdef TARGET_I386
-DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack,
-    "-rtc-td-hack    use it to fix time drift in Windows ACPI HAL\n")
+HXCOMM Deprecated by -rtc
+DEF("rtc-td-hack", 0, QEMU_OPTION_rtc_td_hack, "")
 #endif
-STEXI
-@item -rtc-td-hack
-Use it if you experience time drift problem in Windows with ACPI HAL.
-This option will try to figure out how many timer interrupts were not
-processed by the Windows guest and will re-inject them.
-ETEXI
 
 #ifdef TARGET_I386
 DEF("no-fd-bootchk", 0, QEMU_OPTION_no_fd_bootchk,
@@ -1500,23 +1494,32 @@ Force the use of the given methods for timer alarm. To see what timers
 are available use -clock ?.
 ETEXI
 
-DEF("localtime", 0, QEMU_OPTION_localtime, \
-    "-localtime      set the real time clock to local time [default=utc]\n")
-STEXI
-@item -localtime
-Set the real time clock to local time (the default is to UTC
-time). This option is needed to have correct date in MS-DOS or
-Windows.
-ETEXI
+HXCOMM Options deprecated by -rtc
+DEF("localtime", 0, QEMU_OPTION_localtime, "")
+DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, "")
+
+#ifdef TARGET_I386
+DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
+    "-rtc [base=utc|localtime|date][,driftfix=none|slew]\n" \
+    "                set the RTC base, enable drift fix for clock ticks\n")
+#else
+DEF("rtc", HAS_ARG, QEMU_OPTION_rtc, \
+    "-rtc [base=utc|localtime|date]\n" \
+    "                set the RTC base and clock\n")
+#endif
 
-DEF("startdate", HAS_ARG, QEMU_OPTION_startdate, \
-    "-startdate      select initial date of the clock\n")
 STEXI
 
-@item -startdate @var{date}
-Set the initial date of the real time clock. Valid formats for
-@var{date} are: @code{now} or @code{2006-06-17T16:01:21} or
-@code{2006-06-17}. The default value is @code{now}.
+@item -rtc [base=utc|localtime|@var{date}][,driftfix=none|slew]
+Specify @option{base} as @code{utc} or @code{localtime} to let the RTC start at the current
+UTC or local time, respectively. @code{localtime} is required for correct date in
+MS-DOS or Windows. To start at a specific point in time, provide @var{date} in the
+format @code{2006-06-17T16:01:21} or @code{2006-06-17}. The default base is UTC.
+
+Enable @option{driftfix} (i386 targets only) if you experience time drift problems,
+specifically with Windows' ACPI HAL. This option will try to figure out how
+many timer interrupts were not processed by the Windows guest and will
+re-inject them.
 ETEXI
 
 DEF("icount", HAS_ARG, QEMU_OPTION_icount, \
diff --git a/vl.c b/vl.c
index bf592ec18c..31f3ad2500 100644
--- a/vl.c
+++ b/vl.c
@@ -1582,6 +1582,74 @@ int qemu_timedate_diff(struct tm *tm)
     return seconds - time(NULL);
 }
 
+static void configure_rtc_date_offset(const char *startdate, int legacy)
+{
+    time_t rtc_start_date;
+    struct tm tm;
+
+    if (!strcmp(startdate, "now") && legacy) {
+        rtc_date_offset = -1;
+    } else {
+        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_date = mktimegm(&tm);
+        if (rtc_start_date == -1) {
+        date_fail:
+            fprintf(stderr, "Invalid date format. Valid formats are:\n"
+                            "'2006-06-17T16:01:21' or '2006-06-17'\n");
+            exit(1);
+        }
+        rtc_date_offset = time(NULL) - rtc_start_date;
+    }
+}
+
+static void configure_rtc(QemuOpts *opts)
+{
+    const char *value;
+
+    value = qemu_opt_get(opts, "base");
+    if (value) {
+        if (!strcmp(value, "utc")) {
+            rtc_utc = 1;
+        } else if (!strcmp(value, "localtime")) {
+            rtc_utc = 0;
+        } else {
+            configure_rtc_date_offset(value, 0);
+        }
+    }
+#ifdef CONFIG_TARGET_I386
+    value = qemu_opt_get(opts, "driftfix");
+    if (value) {
+        if (!strcmp(buf, "slew")) {
+            rtc_td_hack = 1;
+        } else if (!strcmp(buf, "none")) {
+            rtc_td_hack = 0;
+        } else {
+            fprintf(stderr, "qemu: invalid option value '%s'\n", value);
+            exit(1);
+        }
+    }
+#endif
+}
+
 #ifdef _WIN32
 static void socket_cleanup(void)
 {
@@ -5382,42 +5450,15 @@ int main(int argc, char **argv, char **envp)
                 configure_alarms(optarg);
                 break;
             case QEMU_OPTION_startdate:
-                {
-                    struct tm tm;
-                    time_t rtc_start_date;
-                    if (!strcmp(optarg, "now")) {
-                        rtc_date_offset = -1;
-                    } else {
-                        if (sscanf(optarg, "%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(optarg, "%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_date = mktimegm(&tm);
-                        if (rtc_start_date == -1) {
-                        date_fail:
-                            fprintf(stderr, "Invalid date format. Valid format are:\n"
-                                    "'now' or '2006-06-17T16:01:21' or '2006-06-17'\n");
-                            exit(1);
-                        }
-                        rtc_date_offset = time(NULL) - rtc_start_date;
-                    }
+                configure_rtc_date_offset(optarg, 1);
+                break;
+            case QEMU_OPTION_rtc:
+                opts = qemu_opts_parse(&qemu_rtc_opts, optarg, NULL);
+                if (!opts) {
+                    fprintf(stderr, "parse error: %s\n", optarg);
+                    exit(1);
                 }
+                configure_rtc(opts);
                 break;
             case QEMU_OPTION_tb_size:
                 tb_size = strtol(optarg, NULL, 0);