This patch adds hmp/qmp commands replay_seek/replay-seek that proceed
the execution to the specified step.
The commands automatically loads nearest snapshot and replay the execution
to find the desired step.
Signed-off-by: Pavel Dovgalyuk <pavel.dovga...@ispras.ru>
--
v2:
- renamed replay_seek qmp command into replay-seek
(suggested by Eric Blake)
---
hmp-commands.hx | 15 ++++++++
hmp.h | 1 +
qapi/misc.json | 16 ++++++++
replay/replay-debugging.c | 89 +++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 121 insertions(+)
diff --git a/hmp-commands.hx b/hmp-commands.hx
index a6d3f12..3bd418e 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1864,6 +1864,21 @@ Execution stops when the specified step is reached.
ETEXI
{
+ .name = "replay_seek",
+ .args_type = "step:i",
+ .params = "step",
+ .help = "rewinds replay to the specified step",
+ .cmd = hmp_replay_seek,
+ },
+
+STEXI
+@item replay_seek @var{step}
+@findex replay_seek
+Automatically proceeds to the specified step, when replaying
+the execution.
+ETEXI
+
+ {
.name = "info",
.args_type = "item:s?",
.params = "[subcommand]",
diff --git a/hmp.h b/hmp.h
index c6b8e37..52ad7b9 100644
--- a/hmp.h
+++ b/hmp.h
@@ -148,5 +148,6 @@ void hmp_info_memory_size_summary(Monitor *mon, const QDict
*qdict);
void hmp_info_sev(Monitor *mon, const QDict *qdict);
void hmp_info_replay(Monitor *mon, const QDict *qdict);
void hmp_replay_break(Monitor *mon, const QDict *qdict);
+void hmp_replay_seek(Monitor *mon, const QDict *qdict);
#endif
diff --git a/qapi/misc.json b/qapi/misc.json
index 71c986a..f8079e1 100644
--- a/qapi/misc.json
+++ b/qapi/misc.json
@@ -3150,6 +3150,22 @@
{ 'command': 'replay-break', 'data': { 'step': 'int' } }
##
+# @replay-seek:
+#
+# Automatically proceeds to the specified step, when replaying
+# the execution.
+#
+# @step: destination execution step
+#
+# Since: 2.13
+#
+# Example:
+#
+# -> { "execute": "replay-seek", "data": { "step": 220414 } }
+##
+{ 'command': 'replay-seek', 'data': { 'step': 'int' } }
+
+##
# @xen-load-devices-state:
#
# Load the state of all devices from file. The RAM and the block devices
diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c
index 819017e..8d6c03d 100644
--- a/replay/replay-debugging.c
+++ b/replay/replay-debugging.c
@@ -18,6 +18,8 @@
#include "qapi/qapi-commands-misc.h"
#include "qapi/qmp/qdict.h"
#include "qemu/timer.h"
+#include "block/snapshot.h"
+#include "migration/snapshot.h"
void hmp_info_replay(Monitor *mon, const QDict *qdict)
{
@@ -94,3 +96,90 @@ void hmp_replay_break(Monitor *mon, const QDict *qdict)
return;
}
}
+
+static char *replay_find_nearest_snapshot(int64_t step, int64_t* snapshot_step)
+{
+ BlockDriverState *bs;
+ QEMUSnapshotInfo *sn_tab;
+ QEMUSnapshotInfo *nearest = NULL;
+ char *ret = NULL;
+ int nb_sns, i;
+ AioContext *aio_context;
+
+ *snapshot_step = -1;
+
+ bs = bdrv_all_find_vmstate_bs();
+ if (!bs) {
+ goto fail;
+ }
+ aio_context = bdrv_get_aio_context(bs);
+
+ aio_context_acquire(aio_context);
+ nb_sns = bdrv_snapshot_list(bs, &sn_tab);
+ aio_context_release(aio_context);
+
+ for (i = 0; i < nb_sns; i++) {
+ if (bdrv_all_find_snapshot(sn_tab[i].name, &bs) == 0) {
+ if (sn_tab[i].icount != -1ULL
+ && sn_tab[i].icount <= step
+ && (!nearest || nearest->icount < sn_tab[i].icount)) {
+ nearest = &sn_tab[i];
+ }
+ }
+ }
+ if (nearest) {
+ ret = g_strdup(nearest->name);
+ *snapshot_step = nearest->icount;
+ }
+ g_free(sn_tab);
+
+fail:
+ return ret;
+}
+
+static void replay_seek(int64_t step, Error **errp, QEMUTimerCB callback)
+{
+ char *snapshot = NULL;
+ if (replay_mode != REPLAY_MODE_PLAY) {
+ error_setg(errp, "replay must be enabled to seek");
+ return;
+ }
+ if (!replay_snapshot) {
+ error_setg(errp, "snapshotting is disabled");
+ return;
+ }
+ int64_t snapshot_step = -1;
+ snapshot = replay_find_nearest_snapshot(step, &snapshot_step);
+ if (snapshot) {
+ if (step < replay_get_current_step()
+ || replay_get_current_step() < snapshot_step) {
+ vm_stop(RUN_STATE_RESTORE_VM);
+ load_snapshot(snapshot, errp);
+ }
+ g_free(snapshot);
+ }
+ if (replay_get_current_step() <= step) {
+ replay_break(step, callback, NULL);
+ vm_start();
+ } else {
+ error_setg(errp, "cannot seek to the specified step");
+ }
+}
+
+void qmp_replay_seek(int64_t step, Error **errp)
+{
+ replay_seek(step, errp, replay_stop_vm);
+}
+
+void hmp_replay_seek(Monitor *mon, const QDict *qdict)
+{
+ int64_t step = qdict_get_try_int(qdict, "step", -1LL);
+ Error *err = NULL;
+
+ qmp_replay_seek(step, &err);
+ if (err) {
+ monitor_printf(mon, "replay_seek error: %s\n", error_get_pretty(err));
+ error_free(err);
+ return;
+ }
+}
