@@ -1820,6 +1820,21 @@ Set QOM property @var{property} of object at location @var{path} to value @var{v
ETEXI
{
+ .name = "replay_break",
+ .args_type = "step:i",
+ .params = "step",
+ .help = "sets breakpoint on the specified step of the replay",
+ .cmd = hmp_replay_break,
+ },
+
+STEXI
+@item replay_break @var{step}
+@findex replay_break
+Set breakpoint on the specified step of the replay.
+Execution stops when the specified step is reached.
+ETEXI
+
+ {
.name = "info",
.args_type = "item:s?",
.params = "[subcommand]",
@@ -145,5 +145,6 @@ void hmp_info_vm_generation_id(Monitor *mon, const QDict *qdict);
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);
#endif
@@ -71,6 +71,9 @@ void replay_start(void);
void replay_finish(void);
/*! Adds replay blocker with the specified error description */
void replay_add_blocker(Error *reason);
+/*! Sets breakpoint at the specified step.
+ If step = -1LL the existing breakpoint is removed. */
+void replay_break(int64_t step, QEMUTimerCB callback, void *opaque);
/* Processing the instructions */
@@ -3099,6 +3099,23 @@
'returns': 'ReplayInfo' }
##
+# @replay-break:
+#
+# Set breakpoint on the specified step of the replay.
+# Execution stops when the specified step is reached.
+#
+# @step: execution step to stop at
+#
+# Since: 2.13
+#
+# Example:
+#
+# -> { "execute": "replay-break", "data": { "step": 220414 } }
+#
+##
+{ 'command': 'replay-break', 'data': { 'step': 'int' } }
+
+##
# @xen-load-devices-state:
#
# Load the state of all devices from file. The RAM and the block devices
@@ -16,6 +16,8 @@
#include "hmp.h"
#include "monitor/monitor.h"
#include "qapi/qapi-commands-misc.h"
+#include "qapi/qmp/qdict.h"
+#include "qemu/timer.h"
void hmp_info_replay(Monitor *mon, const QDict *qdict)
{
@@ -39,3 +41,56 @@ ReplayInfo *qmp_query_replay(Error **errp)
retval->step = replay_get_current_step();
return retval;
}
+
+void replay_break(int64_t step, QEMUTimerCB callback, void *opaque)
+{
+ assert(replay_mode == REPLAY_MODE_PLAY);
+ assert(replay_mutex_locked());
+
+ replay_break_step = step;
+ if (replay_break_timer) {
+ timer_del(replay_break_timer);
+ timer_free(replay_break_timer);
+ replay_break_timer = NULL;
+ }
+
+ if (replay_break_step == -1LL) {
+ return;
+ }
+ assert(replay_break_step >= replay_get_current_step());
+ assert(callback);
+
+ replay_break_timer = timer_new_ns(QEMU_CLOCK_REALTIME, callback, opaque);
+}
+
+static void replay_stop_vm(void *opaque)
+{
+ vm_stop(RUN_STATE_PAUSED);
+ replay_break(-1LL, NULL, NULL);
+}
+
+void qmp_replay_break(int64_t step, Error **errp)
+{
+ if (replay_mode == REPLAY_MODE_PLAY) {
+ if (step >= replay_get_current_step()) {
+ replay_break(step, replay_stop_vm, NULL);
+ } else {
+ error_setg(errp, "cannot set break at the step in the past");
+ }
+ } else {
+ error_setg(errp, "setting the break is allowed only in play mode");
+ }
+}
+
+void hmp_replay_break(Monitor *mon, const QDict *qdict)
+{
+ int64_t step = qdict_get_try_int(qdict, "step", -1LL);
+ Error *err = NULL;
+
+ qmp_replay_break(step, &err);
+ if (err) {
+ monitor_printf(mon, "replay_break error: %s\n", error_get_pretty(err));
+ error_free(err);
+ return;
+ }
+}
@@ -93,6 +93,10 @@ extern ReplayState replay_state;
extern FILE *replay_file;
/*! Name of replay file */
extern char *replay_filename;
+/*! Step of the replay breakpoint */
+extern int64_t replay_break_step;
+/*! Timer for the replay breakpoint callback */
+extern QEMUTimer *replay_break_timer;
void replay_put_byte(uint8_t byte);
void replay_put_event(uint8_t event);
@@ -33,6 +33,10 @@ char *replay_filename;
ReplayState replay_state;
static GSList *replay_blockers;
+/* Replay breakpoints */
+int64_t replay_break_step = -1LL;
+QEMUTimer *replay_break_timer;
+
bool replay_next_event_is(int event)
{
bool res = false;
@@ -72,6 +76,13 @@ int replay_get_instructions(void)
replay_mutex_lock();
if (replay_next_event_is(EVENT_INSTRUCTION)) {
res = replay_state.instructions_count;
+ if (replay_break_step != -1LL) {
+ uint64_t current = replay_get_current_step();
+ assert(replay_break_step >= current);
+ if (current + res > replay_break_step) {
+ res = replay_break_step - current;
+ }
+ }
}
replay_mutex_unlock();
return res;
@@ -98,6 +109,12 @@ void replay_account_executed_instructions(void)
will be read from the log. */
qemu_notify_event();
}
+ /* Execution reached the break step */
+ if (replay_break_step == replay_state.current_step) {
+ /* Cannot make callback directly from the vCPU thread */
+ timer_mod_ns(replay_break_timer,
+ qemu_clock_get_ns(QEMU_CLOCK_REALTIME));
+ }
}
}
}
This patch introduces replay_break qmp and hmp commands. These commands allow stopping at the specified instruction. It may be useful for debugging when there are some known events that should be investigated. The commands have one argument - number of instructions executed since the start of the replay. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> -- v2: - renamed replay_break qmp command into replay-break (suggested by Eric Blake) --- hmp-commands.hx | 15 ++++++++++++ hmp.h | 1 + include/sysemu/replay.h | 3 ++ qapi/misc.json | 17 ++++++++++++++ replay/replay-debugging.c | 55 +++++++++++++++++++++++++++++++++++++++++++++ replay/replay-internal.h | 4 +++ replay/replay.c | 17 ++++++++++++++ 7 files changed, 112 insertions(+)