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[Qemu-devel] [PULL 64/69] replay: avoid recursive call of checkpoints
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PULL 64/69] replay: avoid recursive call of checkpoints |
Date: |
Tue, 13 Mar 2018 23:47:14 +0100 |
From: Pavel Dovgalyuk <address@hidden>
This patch adds a flag which denies recursive call of replay_checkpoint
function. Checkpoints may be accompanied by the hardware events. When event
is processed, virtual device may invoke timer modification functions that
also invoke the checkpoint function. This leads to infinite loop.
Signed-off-by: Pavel Dovgalyuk <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
Signed-off-by: Pavel Dovgalyuk <address@hidden>
---
replay/replay.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/replay/replay.c b/replay/replay.c
index 90f98b7490..eae8daf18a 100644
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -176,13 +176,24 @@ void replay_shutdown_request(ShutdownCause cause)
bool replay_checkpoint(ReplayCheckpoint checkpoint)
{
bool res = false;
+ static bool in_checkpoint;
assert(EVENT_CHECKPOINT + checkpoint <= EVENT_CHECKPOINT_LAST);
- replay_save_instructions();
if (!replay_file) {
return true;
}
+ if (in_checkpoint) {
+ /* If we are already in checkpoint, then there is no need
+ for additional synchronization.
+ Recursion occurs when HW event modifies timers.
+ Timer modification may invoke the checkpoint and
+ proceed to recursion. */
+ return true;
+ }
+ in_checkpoint = true;
+
+ replay_save_instructions();
if (replay_mode == REPLAY_MODE_PLAY) {
g_assert(replay_mutex_locked());
@@ -204,6 +215,7 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint)
res = true;
}
out:
+ in_checkpoint = false;
return res;
}
--
2.14.3
- [Qemu-devel] [PULL 53/69] replay: fix processing async events, (continued)
- [Qemu-devel] [PULL 53/69] replay: fix processing async events, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 54/69] replay: fixed replay_enable_events, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 56/69] replay: added replay log format description, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 55/69] replay: fix save/load vm for non-empty queue, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 57/69] replay: save prior value of the host clock, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 60/69] replay: make locking visible outside replay code, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 59/69] replay/replay-internal.c: track holding of replay_lock, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 58/69] replay/replay.c: bump REPLAY_VERSION again, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 61/69] replay: don't destroy mutex at exit, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 62/69] replay: push replay_mutex_lock up the call tree, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 64/69] replay: avoid recursive call of checkpoints,
Paolo Bonzini <=
- [Qemu-devel] [PULL 63/69] replay: check return values of fwrite, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 65/69] scripts/replay-dump.py: replay log dumper, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 66/69] replay: don't process async events when warping the clock, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 67/69] replay: save vmstate of the asynchronous events, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 68/69] replay: update documentation, Paolo Bonzini, 2018/03/13
- [Qemu-devel] [PULL 69/69] tcg: fix cpu_io_recompile, Paolo Bonzini, 2018/03/13
- Re: [Qemu-devel] [PULL 00/69] Misc patches for QEMU soft freeze, no-reply, 2018/03/13