@@ -1890,6 +1890,35 @@ 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 = "replay_delete_break",
+ .args_type = "",
+ .params = "",
+ .help = "removes replay breakpoint",
+ .cmd = hmp_replay_delete_break,
+ },
+
+STEXI
+@item replay_delete_break
+@findex replay_delete_break
+Removes replay breakpoint which was previously set with replay_break.
+ETEXI
+
+ {
.name = "info",
.args_type = "item:s?",
.params = "[subcommand]",
@@ -149,5 +149,7 @@ 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);
+void hmp_replay_delete_break(Monitor *mon, const QDict *qdict);
#endif
@@ -3148,6 +3148,37 @@
'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: 4.0
+#
+# Example:
+#
+# -> { "execute": "replay-break", "data": { "step": 220414 } }
+#
+##
+{ 'command': 'replay-break', 'data': { 'step': 'int' } }
+
+##
+# @replay-delete-break:
+#
+# Removes replay breakpoint.
+#
+# Since: 4.0
+#
+# Example:
+#
+# -> { "execute": "replay-delete-break" }
+#
+##
+{ 'command': 'replay-delete-break' }
+
+##
# @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)
{
@@ -40,3 +42,85 @@ ReplayInfo *qmp_query_replay(Error **errp)
retval->step = replay_get_current_step();
return retval;
}
+
+static void replay_break(uint64_t step, QEMUTimerCB callback, void *opaque)
+{
+ assert(replay_mode == REPLAY_MODE_PLAY);
+ assert(replay_mutex_locked());
+ assert(replay_break_step >= replay_get_current_step());
+ assert(callback);
+
+ replay_break_step = step;
+
+ if (replay_break_timer) {
+ timer_del(replay_break_timer);
+ } else {
+ replay_break_timer = timer_new_ns(QEMU_CLOCK_REALTIME, callback, opaque);
+ }
+}
+
+static void replay_delete_break(void)
+{
+ assert(replay_mode == REPLAY_MODE_PLAY);
+ assert(replay_mutex_locked());
+
+ if (replay_break_timer) {
+ timer_del(replay_break_timer);
+ timer_free(replay_break_timer);
+ replay_break_timer = NULL;
+ }
+ replay_break_step = -1ULL;
+}
+
+static void replay_stop_vm(void *opaque)
+{
+ vm_stop(RUN_STATE_PAUSED);
+ replay_delete_break();
+}
+
+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 breakpoint at the step in the past");
+ }
+ } else {
+ error_setg(errp, "setting the breakpoint 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) {
+ error_report_err(err);
+ error_free(err);
+ return;
+ }
+}
+
+void qmp_replay_delete_break(Error **errp)
+{
+ if (replay_mode == REPLAY_MODE_PLAY) {
+ replay_delete_break();
+ } else {
+ error_setg(errp, "replay breakpoints are allowed only in play mode");
+ }
+}
+
+void hmp_replay_delete_break(Monitor *mon, const QDict *qdict)
+{
+ Error *err = NULL;
+
+ qmp_replay_delete_break(&err);
+ if (err) {
+ error_report_err(err);
+ error_free(err);
+ return;
+ }
+}
@@ -91,6 +91,10 @@ extern ReplayState replay_state;
/* File for replay writing */
extern FILE *replay_file;
+/* Step of the replay breakpoint */
+extern uint64_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);
@@ -34,6 +34,10 @@ static char *replay_filename;
ReplayState replay_state;
static GSList *replay_blockers;
+/* Replay breakpoints */
+uint64_t replay_break_step = -1ULL;
+QEMUTimer *replay_break_timer;
+
bool replay_next_event_is(int event)
{
bool res = false;
@@ -73,6 +77,13 @@ 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;
@@ -99,6 +110,12 @@ 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, replay_delete_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. replay_break command has one argument - number of instructions executed since the start of the replay. replay_delete_break removes previously set breakpoint. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> -- v2: - renamed replay_break qmp command into replay-break (suggested by Eric Blake) v7: - introduces replay_delete_break command --- hmp-commands.hx | 29 ++++++++++++++++ hmp.h | 2 + qapi/misc.json | 31 +++++++++++++++++ replay/replay-debugging.c | 84 +++++++++++++++++++++++++++++++++++++++++++++ replay/replay-internal.h | 4 ++ replay/replay.c | 17 +++++++++ 6 files changed, 167 insertions(+)