[Qemu-devel] [PATCH 2/3] replay: allow replay stopping and restarting

[Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>]

This patch fixes bug with stopping and restarting replay
through monitor.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
---
 block/blkreplay.c        |   18 +++++++++++++-----
 cpus.c                   |    1 +
 include/sysemu/replay.h  |    2 ++
 replay/replay-internal.h |    2 --
 vl.c                     |    1 +
 5 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/block/blkreplay.c b/block/blkreplay.c
index 42f1813..438170c 100644
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -70,6 +70,14 @@ static void blkreplay_bh_cb(void *opaque)
     g_free(req);
 }
 
+static uint64_t blkreplay_next_id(void)
+{
+    if (replay_events_enabled()) {
+        return request_id++;
+    }
+    return 0;
+}
+
 static void block_request_create(uint64_t reqid, BlockDriverState *bs,
                                  Coroutine *co)
 {
@@ -84,7 +92,7 @@ static void block_request_create(uint64_t reqid, BlockDriverState *bs,
 static int coroutine_fn blkreplay_co_readv(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 {
-    uint64_t reqid = request_id++;
+    uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_readv(bs->file->bs, sector_num, nb_sectors, qiov);
     block_request_create(reqid, bs, qemu_coroutine_self());
     qemu_coroutine_yield();
@@ -95,7 +103,7 @@ static int coroutine_fn blkreplay_co_readv(BlockDriverState *bs,
 static int coroutine_fn blkreplay_co_writev(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
 {
-    uint64_t reqid = request_id++;
+    uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_writev(bs->file->bs, sector_num, nb_sectors, qiov);
     block_request_create(reqid, bs, qemu_coroutine_self());
     qemu_coroutine_yield();
@@ -106,7 +114,7 @@ static int coroutine_fn blkreplay_co_writev(BlockDriverState *bs,
 static int coroutine_fn blkreplay_co_write_zeroes(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
 {
-    uint64_t reqid = request_id++;
+    uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_write_zeroes(bs->file->bs, sector_num, nb_sectors, flags);
     block_request_create(reqid, bs, qemu_coroutine_self());
     qemu_coroutine_yield();
@@ -117,7 +125,7 @@ static int coroutine_fn blkreplay_co_write_zeroes(BlockDriverState *bs,
 static int coroutine_fn blkreplay_co_discard(BlockDriverState *bs,
     int64_t sector_num, int nb_sectors)
 {
-    uint64_t reqid = request_id++;
+    uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_discard(bs->file->bs, sector_num, nb_sectors);
     block_request_create(reqid, bs, qemu_coroutine_self());
     qemu_coroutine_yield();
@@ -127,7 +135,7 @@ static int coroutine_fn blkreplay_co_discard(BlockDriverState *bs,
 
 static int coroutine_fn blkreplay_co_flush(BlockDriverState *bs)
 {
-    uint64_t reqid = request_id++;
+    uint64_t reqid = blkreplay_next_id();
     int ret = bdrv_co_flush(bs->file->bs);
     block_request_create(reqid, bs, qemu_coroutine_self());
     qemu_coroutine_yield();
diff --git a/cpus.c b/cpus.c
index 326742f..34f951f 100644
--- a/cpus.c
+++ b/cpus.c
@@ -742,6 +742,7 @@ static int do_vm_stop(RunState state)
         runstate_set(state);
         vm_state_notify(0, state);
         qapi_event_send_stop(&error_abort);
+        replay_disable_events();
     }
 
     bdrv_drain_all();
diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h
index 0a88393..52430d3 100644
--- a/include/sysemu/replay.h
+++ b/include/sysemu/replay.h
@@ -105,6 +105,8 @@ bool replay_checkpoint(ReplayCheckpoint checkpoint);
 
 /*! Disables storing events in the queue */
 void replay_disable_events(void);
+/*! Enables storing events in the queue */
+void replay_enable_events(void);
 /*! Returns true when saving events is enabled */
 bool replay_events_enabled(void);
 /*! Adds bottom half event to the queue */
diff --git a/replay/replay-internal.h b/replay/replay-internal.h
index efbf14c..310c4b7 100644
--- a/replay/replay-internal.h
+++ b/replay/replay-internal.h
@@ -119,8 +119,6 @@ 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);
-/*! Enables storing events in the queue */
-void replay_enable_events(void);
 /*! Flushes events queue */
 void replay_flush_events(void);
 /*! Clears events list before loading new VM state */
diff --git a/vl.c b/vl.c
index 2f74fe8..b361ca8 100644
--- a/vl.c
+++ b/vl.c
@@ -765,6 +765,7 @@ void vm_start(void)
     if (runstate_is_running()) {
         qapi_event_send_stop(&error_abort);
     } else {
+        replay_enable_events();
         cpu_enable_ticks();
         runstate_set(RUN_STATE_RUNNING);
         vm_state_notify(1, RUN_STATE_RUNNING);