From patchwork Mon Sep 14 06:07:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 1363247 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=ispras.ru Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4BqbX66slcz9sTR for ; Mon, 14 Sep 2020 16:08:38 +1000 (AEST) Received: from localhost ([::1]:56816 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kHhfH-0005TY-DO for incoming@patchwork.ozlabs.org; Mon, 14 Sep 2020 02:08:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36920) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kHhdv-0003Is-6y for qemu-devel@nongnu.org; Mon, 14 Sep 2020 02:07:11 -0400 Received: from mail.ispras.ru ([83.149.199.84]:44934) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kHhds-0002NK-Ue for qemu-devel@nongnu.org; Mon, 14 Sep 2020 02:07:10 -0400 Received: from [127.0.1.1] (unknown [62.118.151.149]) by mail.ispras.ru (Postfix) with ESMTPSA id D9CC740D3BFF; Mon, 14 Sep 2020 06:07:06 +0000 (UTC) Subject: [PATCH v4 07/15] replay: introduce breakpoint at the specified step From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Mon, 14 Sep 2020 09:07:06 +0300 Message-ID: <160006362654.31457.5024270491146336329.stgit@pasha-ThinkPad-X280> In-Reply-To: <160006358590.31457.16757371597343007847.stgit@pasha-ThinkPad-X280> References: <160006358590.31457.16757371597343007847.stgit@pasha-ThinkPad-X280> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/14 02:06:27 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Pavel Dovgalyuk 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 Acked-by: Markus Armbruster --- v4 changes: - removed useless error_free call --- hmp-commands.hx | 32 +++++++++++++++++ include/monitor/hmp.h | 2 + qapi/replay.json | 36 +++++++++++++++++++ replay/replay-debugging.c | 84 +++++++++++++++++++++++++++++++++++++++++++++ replay/replay-internal.h | 4 ++ replay/replay.c | 17 +++++++++ 6 files changed, 175 insertions(+) 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 e6b3f6001d..173ba76107 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: 5.2 +# +# 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: 5.2 +# +# Example: +# +# -> { "execute": "replay-delete-break" } +# +## +{ 'command': 'replay-delete-break' } diff --git a/replay/replay-debugging.c b/replay/replay-debugging.c index 51a6de4e81..3dc23b84fc 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 +44,84 @@ 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); + 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); + 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)); + } } } }