From: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
To: qemu-devel@nongnu.org
Cc: kwolf@redhat.com, wrampazz@redhat.com, pavel.dovgalyuk@ispras.ru,
ehabkost@redhat.com, alex.bennee@linaro.org, mtosatti@redhat.com,
armbru@redhat.com, mreitz@redhat.com, stefanha@redhat.com,
crosa@redhat.com, pbonzini@redhat.com, philmd@redhat.com,
zhiwei_liu@c-sky.com, rth@twiddle.net
Subject: [PATCH 07/13] replay: introduce breakpoint at the specified step
Date: Fri, 26 Jun 2020 13:20:20 +0300 [thread overview]
Message-ID: <159316681996.10508.1440640483514730623.stgit@pasha-ThinkPad-X280> (raw)
In-Reply-To: <159316678008.10508.6615172353109944370.stgit@pasha-ThinkPad-X280>
From: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
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.Dovgalyuk@ispras.ru>
Acked-by: Markus Armbruster <armbru@redhat.com>
---
0 files changed
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 60f395c276..e8ce385879 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1819,6 +1819,38 @@ SRST
Set QOM property *property* of object at location *path* to value *value*
ERST
+ {
+ .name = "replay_break",
+ .args_type = "icount:i",
+ .params = "icount",
+ .help = "set breakpoint at the specified instruction count",
+ .cmd = hmp_replay_break,
+ },
+
+SRST
+``replay_break`` *icount*
+ Set replay breakpoint at instruction count *icount*.
+ Execution stops when the specified instruction is reached.
+ There can be at most one breakpoint. When breakpoint is set, any prior
+ one is removed. The breakpoint may be set only in replay mode and only
+ "in the future", i.e. at instruction counts greater than the current one.
+ The current instruction count can be observed with ``info replay``.
+ERST
+
+ {
+ .name = "replay_delete_break",
+ .args_type = "",
+ .params = "",
+ .help = "remove replay breakpoint",
+ .cmd = hmp_replay_delete_break,
+ },
+
+SRST
+``replay_delete_break``
+ Remove replay breakpoint which was previously set with ``replay_break``.
+ The command is ignored when there are no replay breakpoints.
+ERST
+
{
.name = "info",
.args_type = "item:s?",
diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
index a790589b9e..21849bdda5 100644
--- a/include/monitor/hmp.h
+++ b/include/monitor/hmp.h
@@ -131,5 +131,7 @@ 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
diff --git a/qapi/replay.json b/qapi/replay.json
index 0a160466f2..edf7cc9265 100644
--- a/qapi/replay.json
+++ b/qapi/replay.json
@@ -63,3 +63,39 @@
##
{ 'command': 'query-replay',
'returns': 'ReplayInfo' }
+
+##
+# @replay-break:
+#
+# Set replay breakpoint at instruction count @icount.
+# Execution stops when the specified instruction is reached.
+# There can be at most one breakpoint. When breakpoint is set, any prior
+# one is removed. The breakpoint may be set only in replay mode and only
+# "in the future", i.e. at instruction counts greater than the current one.
+# The current instruction count can be observed with @query-replay.
+#
+# @icount: instruction count to stop at
+#
+# Since: 5.1
+#
+# Example:
+#
+# -> { "execute": "replay-break", "data": { "icount": 220414 } }
+#
+##
+{ 'command': 'replay-break', 'data': { 'icount': 'int' } }
+
+##
+# @replay-delete-break:
+#
+# Remove replay breakpoint which was set with @replay-break.
+# The command is ignored when there are no replay breakpoints.
+#
+# Since: 5.1
+#
+# Example:
+#
+# -> { "execute": "replay-delete-break" }
+#
+##
+{ 'command': 'replay-delete-break' }
diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c
index 51a6de4e81..86e19bb217 100644
--- a/replay/replay-debugging.c
+++ b/replay/replay-debugging.c
@@ -12,10 +12,13 @@
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "sysemu/replay.h"
+#include "sysemu/runstate.h"
#include "replay-internal.h"
#include "monitor/hmp.h"
#include "monitor/monitor.h"
#include "qapi/qapi-commands-replay.h"
+#include "qapi/qmp/qdict.h"
+#include "qemu/timer.h"
void hmp_info_replay(Monitor *mon, const QDict *qdict)
{
@@ -41,3 +44,86 @@ ReplayInfo *qmp_query_replay(Error **errp)
retval->icount = replay_get_current_icount();
return retval;
}
+
+static void replay_break(uint64_t icount, QEMUTimerCB callback, void *opaque)
+{
+ assert(replay_mode == REPLAY_MODE_PLAY);
+ assert(replay_mutex_locked());
+ assert(replay_break_icount >= replay_get_current_icount());
+ assert(callback);
+
+ replay_break_icount = icount;
+
+ if (replay_break_timer) {
+ timer_del(replay_break_timer);
+ }
+ 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_icount = -1ULL;
+}
+
+static void replay_stop_vm(void *opaque)
+{
+ vm_stop(RUN_STATE_PAUSED);
+ replay_delete_break();
+}
+
+void qmp_replay_break(int64_t icount, Error **errp)
+{
+ if (replay_mode == REPLAY_MODE_PLAY) {
+ if (icount >= replay_get_current_icount()) {
+ replay_break(icount, replay_stop_vm, NULL);
+ } else {
+ error_setg(errp,
+ "cannot set breakpoint at the instruction 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 icount = qdict_get_try_int(qdict, "icount", -1LL);
+ Error *err = NULL;
+
+ qmp_replay_break(icount, &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;
+ }
+}
diff --git a/replay/replay-internal.h b/replay/replay-internal.h
index 33ac551e78..2f6145ec7c 100644
--- a/replay/replay-internal.h
+++ b/replay/replay-internal.h
@@ -94,6 +94,10 @@ extern ReplayState replay_state;
/* File for replay writing */
extern FILE *replay_file;
+/* Instruction count of the replay breakpoint */
+extern uint64_t replay_break_icount;
+/* 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);
diff --git a/replay/replay.c b/replay/replay.c
index 42e82f7bc7..220886e32e 100644
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -34,6 +34,10 @@ static char *replay_filename;
ReplayState replay_state;
static GSList *replay_blockers;
+/* Replay breakpoints */
+uint64_t replay_break_icount = -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.instruction_count;
+ if (replay_break_icount != -1LL) {
+ uint64_t current = replay_get_current_icount();
+ assert(replay_break_icount >= current);
+ if (current + res > replay_break_icount) {
+ res = replay_break_icount - 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_icount == replay_state.current_icount) {
+ /* Cannot make callback directly from the vCPU thread */
+ timer_mod_ns(replay_break_timer,
+ qemu_clock_get_ns(QEMU_CLOCK_REALTIME));
+ }
}
}
}
next prev parent reply other threads:[~2020-06-26 13:44 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-26 10:19 [PATCH 00/13] Reverse debugging Pavel Dovgalyuk
2020-06-26 10:19 ` [PATCH 01/13] replay: provide an accessor for rr filename Pavel Dovgalyuk
2020-06-26 10:19 ` [PATCH 02/13] qcow2: introduce icount field for snapshots Pavel Dovgalyuk
2020-07-06 20:17 ` Eric Blake
2020-07-16 6:43 ` Pavel Dovgalyuk
2020-06-26 10:19 ` [PATCH 03/13] migration: " Pavel Dovgalyuk
2020-06-26 10:20 ` [PATCH 04/13] iotests: update snapshot test for new output format Pavel Dovgalyuk
2020-06-26 10:20 ` [PATCH 05/13] qapi: introduce replay.json for record/replay-related stuff Pavel Dovgalyuk
2020-07-15 11:20 ` Alex Bennée
2020-07-16 6:00 ` Pavel Dovgalyuk
2020-06-26 10:20 ` [PATCH 06/13] replay: introduce info hmp/qmp command Pavel Dovgalyuk
2020-06-26 10:20 ` Pavel Dovgalyuk [this message]
2020-06-26 10:20 ` [PATCH 08/13] replay: implement replay-seek command Pavel Dovgalyuk
2020-06-26 10:20 ` [PATCH 09/13] replay: flush rr queue before loading the vmstate Pavel Dovgalyuk
2020-06-26 10:20 ` [PATCH 10/13] gdbstub: add reverse step support in replay mode Pavel Dovgalyuk
2020-07-15 11:27 ` Alex Bennée
2020-06-26 10:20 ` [PATCH 11/13] gdbstub: add reverse continue " Pavel Dovgalyuk
2020-06-26 10:20 ` [PATCH 12/13] replay: describe reverse debugging in docs/replay.txt Pavel Dovgalyuk
2020-06-26 10:20 ` [PATCH 13/13] tests/acceptance: add reverse debugging test Pavel Dovgalyuk
2020-07-06 6:02 ` [PATCH 00/13] Reverse debugging Pavel Dovgalyuk
2020-07-06 19:55 ` Alex Bennée
2020-07-07 5:00 ` Pavel Dovgalyuk
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