From 1dfb1b2d34840dce27e672f147bc4ef122abab74 Mon Sep 17 00:00:00 2001 From: Pavel Dovgalyuk Date: Tue, 24 Jan 2017 10:17:30 +0300 Subject: replay: don't use rtc clock on loadvm phase This patch disables the update of the periodic timer of mc146818rtc in record/replay mode. State of this timer is saved and therefore does not need to be updated in record/replay mode. Read of RTC breaks the replay because all rtc reads have to be the same as in record mode. Signed-off-by: Pavel Dovgalyuk Message-Id: <20170124071730.4572.41874.stgit@PASHA-ISP> Signed-off-by: Paolo Bonzini --- hw/timer/mc146818rtc.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'hw/timer/mc146818rtc.c') diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c index 637f8722a7..4165450250 100644 --- a/hw/timer/mc146818rtc.c +++ b/hw/timer/mc146818rtc.c @@ -27,6 +27,7 @@ #include "hw/hw.h" #include "qemu/timer.h" #include "sysemu/sysemu.h" +#include "sysemu/replay.h" #include "hw/timer/mc146818rtc.h" #include "qapi/visitor.h" #include "qapi-event.h" @@ -734,10 +735,16 @@ static int rtc_post_load(void *opaque, int version_id) check_update_timer(s); } - uint64_t now = qemu_clock_get_ns(rtc_clock); - if (now < s->next_periodic_time || - now > (s->next_periodic_time + get_max_clock_jump())) { - periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + /* The periodic timer is deterministic in record/replay mode, + * so there is no need to update it after loading the vmstate. + * Reading RTC here would misalign record and replay. + */ + if (replay_mode == REPLAY_MODE_NONE) { + uint64_t now = qemu_clock_get_ns(rtc_clock); + if (now < s->next_periodic_time || + now > (s->next_periodic_time + get_max_clock_jump())) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + } } #ifdef TARGET_I386 -- cgit v1.2.3