[Qemu-devel] [PATCH v3 2/2] Change timedrift default value to slew

[Crístian Viana]

Windows 2008+ is very sensitive to missed ticks. The RTC is used by default as
the time source.  If time drift is not enabled, Windows is prone to
blue screening.

Signed-off-by: Crístian Viana <address@hidden>
---
 hw/mc146818rtc.c |    2 +-
 vl.c             |   10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c
index 2b59c36..2b31587 100644
--- a/hw/mc146818rtc.c
+++ b/hw/mc146818rtc.c
@@ -726,7 +726,7 @@ ISADevice *rtc_init(ISABus *bus, int base_year, qemu_irq 
intercept_irq)
 static Property mc146818rtc_properties[] = {
     DEFINE_PROP_INT32("base_year", RTCState, base_year, 1980),
     DEFINE_PROP_LOSTTICKPOLICY("lost_tick_policy", RTCState,
-                               lost_tick_policy, LOST_TICK_DISCARD),
+                               lost_tick_policy, LOST_TICK_SLEW),
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/vl.c b/vl.c
index 112b0e0..11817e5 100644
--- a/vl.c
+++ b/vl.c
@@ -539,18 +539,18 @@ static void configure_rtc(QemuOpts *opts)
     value = qemu_opt_get(opts, "driftfix");
     if (value) {
         if (!strcmp(value, "slew")) {
-            static GlobalProperty slew_lost_ticks[] = {
+            /* slew is default */
+        } else if (!strcmp(value, "none")) {
+            static GlobalProperty discard_lost_ticks[] = {
                 {
                     .driver   = "mc146818rtc",
                     .property = "lost_tick_policy",
-                    .value    = "slew",
+                    .value    = "discard",
                 },
                 { /* end of list */ }
             };
 
-            qdev_prop_register_global_list(slew_lost_ticks);
-        } else if (!strcmp(value, "none")) {
-            /* discard is default */
+            qdev_prop_register_global_list(discard_lost_ticks);
         } else {
             fprintf(stderr, "qemu: invalid option value '%s'\n", value);
             exit(1);
-- 
1.7.8.5