#include "qapi/qapi-commands-replay.h"
#include "qapi/qmp/qdict.h"
#include "qemu/timer.h"
+#include "block/snapshot.h"
+#include "migration/snapshot.h"
+
+static bool replay_is_debugging;
+static int64_t replay_last_breakpoint;
+static int64_t replay_last_snapshot;
+
+bool replay_running_debug(void)
+{
+ return replay_is_debugging;
+}
void hmp_info_replay(Monitor *mon, const QDict *qdict)
{
assert(replay_mutex_locked());
if (replay_break_timer) {
- timer_del(replay_break_timer);
timer_free(replay_break_timer);
replay_break_timer = NULL;
}
return;
}
}
+
+static char *replay_find_nearest_snapshot(int64_t icount,
+ int64_t *snapshot_icount)
+{
+ BlockDriverState *bs;
+ QEMUSnapshotInfo *sn_tab;
+ QEMUSnapshotInfo *nearest = NULL;
+ char *ret = NULL;
+ int rv;
+ int nb_sns, i;
+ AioContext *aio_context;
+
+ *snapshot_icount = -1;
+
+ bs = bdrv_all_find_vmstate_bs(NULL, false, NULL, NULL);
+ 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++) {
+ rv = bdrv_all_has_snapshot(sn_tab[i].name, false, NULL, NULL);
+ if (rv < 0)
+ goto fail;
+ if (rv == 1) {
+ if (sn_tab[i].icount != -1ULL
+ && sn_tab[i].icount <= icount
+ && (!nearest || nearest->icount < sn_tab[i].icount)) {
+ nearest = &sn_tab[i];
+ }
+ }
+ }
+ if (nearest) {
+ ret = g_strdup(nearest->name);
+ *snapshot_icount = nearest->icount;
+ }
+ g_free(sn_tab);
+
+fail:
+ return ret;
+}
+
+static void replay_seek(int64_t icount, QEMUTimerCB callback, Error **errp)
+{
+ char *snapshot = NULL;
+ int64_t snapshot_icount;
+
+ if (replay_mode != REPLAY_MODE_PLAY) {
+ error_setg(errp, "replay must be enabled to seek");
+ return;
+ }
+
+ snapshot = replay_find_nearest_snapshot(icount, &snapshot_icount);
+ if (snapshot) {
+ if (icount < replay_get_current_icount()
+ || replay_get_current_icount() < snapshot_icount) {
+ vm_stop(RUN_STATE_RESTORE_VM);
+ load_snapshot(snapshot, NULL, false, NULL, errp);
+ }
+ g_free(snapshot);
+ }
+ if (replay_get_current_icount() <= icount) {
+ replay_break(icount, callback, NULL);
+ vm_start();
+ } else {
+ error_setg(errp, "cannot seek to the specified instruction count");
+ }
+}
+
+void qmp_replay_seek(int64_t icount, Error **errp)
+{
+ replay_seek(icount, replay_stop_vm, errp);
+}
+
+void hmp_replay_seek(Monitor *mon, const QDict *qdict)
+{
+ int64_t icount = qdict_get_try_int(qdict, "icount", -1LL);
+ Error *err = NULL;
+
+ qmp_replay_seek(icount, &err);
+ if (err) {
+ error_report_err(err);
+ return;
+ }
+}
+
+static void replay_stop_vm_debug(void *opaque)
+{
+ replay_is_debugging = false;
+ vm_stop(RUN_STATE_DEBUG);
+ replay_delete_break();
+}
+
+bool replay_reverse_step(void)
+{
+ Error *err = NULL;
+
+ assert(replay_mode == REPLAY_MODE_PLAY);
+
+ if (replay_get_current_icount() != 0) {
+ replay_seek(replay_get_current_icount() - 1,
+ replay_stop_vm_debug, &err);
+ if (err) {
+ error_free(err);
+ return false;
+ }
+ replay_is_debugging = true;
+ return true;
+ }
+
+ return false;
+}
+
+static void replay_continue_end(void)
+{
+ replay_is_debugging = false;
+ vm_stop(RUN_STATE_DEBUG);
+ replay_delete_break();
+}
+
+static void replay_continue_stop(void *opaque)
+{
+ Error *err = NULL;
+ if (replay_last_breakpoint != -1LL) {
+ replay_seek(replay_last_breakpoint, replay_stop_vm_debug, &err);
+ if (err) {
+ error_free(err);
+ replay_continue_end();
+ }
+ return;
+ }
+ /*
+ * No breakpoints since the last snapshot.
+ * Find previous snapshot and try again.
+ */
+ if (replay_last_snapshot != 0) {
+ replay_seek(replay_last_snapshot - 1, replay_continue_stop, &err);
+ if (err) {
+ error_free(err);
+ replay_continue_end();
+ }
+ replay_last_snapshot = replay_get_current_icount();
+ } else {
+ /* Seek to the very first step */
+ replay_seek(0, replay_stop_vm_debug, &err);
+ if (err) {
+ error_free(err);
+ replay_continue_end();
+ }
+ }
+}
+
+bool replay_reverse_continue(void)
+{
+ Error *err = NULL;
+
+ assert(replay_mode == REPLAY_MODE_PLAY);
+
+ if (replay_get_current_icount() != 0) {
+ replay_seek(replay_get_current_icount() - 1,
+ replay_continue_stop, &err);
+ if (err) {
+ error_free(err);
+ return false;
+ }
+ replay_last_breakpoint = -1LL;
+ replay_is_debugging = true;
+ replay_last_snapshot = replay_get_current_icount();
+ return true;
+ }
+
+ return false;
+}
+
+void replay_breakpoint(void)
+{
+ assert(replay_mode == REPLAY_MODE_PLAY);
+ replay_last_breakpoint = replay_get_current_icount();
+}
+
+void replay_gdb_attached(void)
+{
+ /*
+ * Create VM snapshot on temporary overlay to allow reverse
+ * debugging even if snapshots were not enabled.
+ */
+ if (replay_mode == REPLAY_MODE_PLAY
+ && !replay_snapshot) {
+ if (!save_snapshot("start_debugging", true, NULL, false, NULL, NULL)) {
+ /* Can't create the snapshot. Continue conventional debugging. */
+ }
+ }
+}