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[Qemu-devel] [PULL 03/41] replay: don't use rtc clock on loadvm phase
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 03/41] replay: don't use rtc clock on loadvm phase |
Date: |
Fri, 27 Jan 2017 14:45:11 +0100 |
From: Pavel Dovgalyuk <address@hidden>
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 <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
hw/timer/mc146818rtc.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
index 637f872..4165450 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
--
1.8.3.1
- [Qemu-devel] [PULL 00/41] Misc changes for 2017-01-27, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 03/41] replay: don't use rtc clock on loadvm phase,
Paolo Bonzini <=
- [Qemu-devel] [PULL 04/41] savevm: add public save_vmstate function, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 05/41] replay: save/load initial state, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 01/41] icount: update instruction counter on apic patching, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 02/41] replay: improve interrupt handling, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 06/41] replay: exception replay fix, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 07/41] apic: save apic_delivered flag, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 08/41] memory: tune mtree_print_mr() to dump mr type, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 12/41] hw/isa/lpc_ich9: negotiate SMI broadcast on pc-q35-2.9+ machine types, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 11/41] hw/isa/lpc_ich9: add broadcast SMI feature, Paolo Bonzini, 2017/01/27
- [Qemu-devel] [PULL 13/41] block/iscsi: avoid data corruption with cache=writeback, Paolo Bonzini, 2017/01/27