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[PULL 32/37] replay: flush rr queue before loading the vmstate
From: |
Paolo Bonzini |
Subject: |
[PULL 32/37] replay: flush rr queue before loading the vmstate |
Date: |
Tue, 6 Oct 2020 09:29:42 +0200 |
From: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Non-empty record/replay queue prevents saving and loading the VM state,
because it includes pending bottom halves and block coroutines.
But when the new VM state is loaded, we don't have to preserve the consistency
of the current state anymore. Therefore this patch just flushes the queue
allowing the coroutines to finish and removes checking for empty rr queue
for load_snapshot function.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <160174521762.12451.15752448887893855757.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
include/sysemu/replay.h | 2 ++
migration/savevm.c | 12 ++++++------
replay/replay-events.c | 4 ++++
replay/replay-internal.h | 2 --
4 files changed, 12 insertions(+), 8 deletions(-)
diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h
index d6026ed8e5..c486c3afb2 100644
--- a/include/sysemu/replay.h
+++ b/include/sysemu/replay.h
@@ -149,6 +149,8 @@ void replay_disable_events(void);
void replay_enable_events(void);
/*! Returns true when saving events is enabled */
bool replay_events_enabled(void);
+/* Flushes events queue */
+void replay_flush_events(void);
/*! Adds bottom half event to the queue */
void replay_bh_schedule_event(QEMUBH *bh);
/* Adds oneshot bottom half event to the queue */
diff --git a/migration/savevm.c b/migration/savevm.c
index 0e8dc78684..d2e141f7b1 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2881,12 +2881,6 @@ int load_snapshot(const char *name, Error **errp)
AioContext *aio_context;
MigrationIncomingState *mis = migration_incoming_get_current();
- if (!replay_can_snapshot()) {
- error_setg(errp, "Record/replay does not allow loading snapshot "
- "right now. Try once more later.");
- return -EINVAL;
- }
-
if (!bdrv_all_can_snapshot(&bs)) {
error_setg(errp,
"Device '%s' is writable but does not support snapshots",
@@ -2920,6 +2914,12 @@ int load_snapshot(const char *name, Error **errp)
return -EINVAL;
}
+ /*
+ * Flush the record/replay queue. Now the VM state is going
+ * to change. Therefore we don't need to preserve its consistency
+ */
+ replay_flush_events();
+
/* Flush all IO requests so they don't interfere with the new state. */
bdrv_drain_all_begin();
diff --git a/replay/replay-events.c b/replay/replay-events.c
index 302b84043a..a1c6bb934e 100644
--- a/replay/replay-events.c
+++ b/replay/replay-events.c
@@ -77,6 +77,10 @@ bool replay_has_events(void)
void replay_flush_events(void)
{
+ if (replay_mode == REPLAY_MODE_NONE) {
+ return;
+ }
+
g_assert(replay_mutex_locked());
while (!QTAILQ_EMPTY(&events_list)) {
diff --git a/replay/replay-internal.h b/replay/replay-internal.h
index 2f6145ec7c..97649ed8d7 100644
--- a/replay/replay-internal.h
+++ b/replay/replay-internal.h
@@ -149,8 +149,6 @@ void replay_read_next_clock(unsigned int kind);
void replay_init_events(void);
/*! Clears internal data structures for events handling */
void replay_finish_events(void);
-/*! Flushes events queue */
-void replay_flush_events(void);
/*! Returns true if there are any unsaved events in the queue */
bool replay_has_events(void);
/*! Saves events from queue into the file */
--
2.26.2
- [PULL 25/37] replay: provide an accessor for rr filename, (continued)
- [PULL 25/37] replay: provide an accessor for rr filename, Paolo Bonzini, 2020/10/06
- [PULL 21/37] configure: do not clobber environment CFLAGS/CXXFLAGS/LDFLAGS, Paolo Bonzini, 2020/10/06
- [PULL 24/37] replay: don't record interrupt poll, Paolo Bonzini, 2020/10/06
- [PULL 26/37] qcow2: introduce icount field for snapshots, Paolo Bonzini, 2020/10/06
- [PULL 27/37] migration: introduce icount field for snapshots, Paolo Bonzini, 2020/10/06
- [PULL 28/37] qapi: introduce replay.json for record/replay-related stuff, Paolo Bonzini, 2020/10/06
- [PULL 29/37] replay: introduce info hmp/qmp command, Paolo Bonzini, 2020/10/06
- [PULL 30/37] replay: introduce breakpoint at the specified step, Paolo Bonzini, 2020/10/06
- [PULL 35/37] replay: describe reverse debugging in docs/replay.txt, Paolo Bonzini, 2020/10/06
- [PULL 32/37] replay: flush rr queue before loading the vmstate,
Paolo Bonzini <=
- [PULL 31/37] replay: implement replay-seek command, Paolo Bonzini, 2020/10/06
- [PULL 33/37] gdbstub: add reverse step support in replay mode, Paolo Bonzini, 2020/10/06
- [PULL 34/37] gdbstub: add reverse continue support in replay mode, Paolo Bonzini, 2020/10/06
- [PULL 36/37] replay: create temporary snapshot at debugger connection, Paolo Bonzini, 2020/10/06
- [PULL 37/37] tests/acceptance: add reverse debugging test, Paolo Bonzini, 2020/10/06
- Re: [PULL 00/37] Build system + accel + record/replay patches for 2020-10-06, Peter Maydell, 2020/10/06