From patchwork Tue Feb 16 12:51:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Dovgalyuk X-Patchwork-Id: 1440904 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=) 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 4Dg18c3DYmz9sVF for ; Tue, 16 Feb 2021 23:52:30 +1100 (AEDT) Received: from localhost ([::1]:59418 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lBzq7-00064V-6u for incoming@patchwork.ozlabs.org; Tue, 16 Feb 2021 07:52:27 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:57764) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lBzpb-00063a-KW for qemu-devel@nongnu.org; Tue, 16 Feb 2021 07:51:55 -0500 Received: from mail.ispras.ru ([83.149.199.84]:46156) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lBzpY-0003ZA-V4 for qemu-devel@nongnu.org; Tue, 16 Feb 2021 07:51:55 -0500 Received: from [127.0.1.1] (unknown [62.118.151.149]) by mail.ispras.ru (Postfix) with ESMTPSA id 27A0040755FA; Tue, 16 Feb 2021 12:51:45 +0000 (UTC) Subject: [PATCH] replay: fix icount request when replaying clock access From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Tue, 16 Feb 2021 15:51:44 +0300 Message-ID: <161347990483.1313189.8371838968343494161.stgit@pasha-ThinkPad-X280> User-Agent: StGit/0.23 MIME-Version: 1.0 Received-SPF: pass client-ip=83.149.199.84; envelope-from=pavel.dovgalyuk@ispras.ru; helo=mail.ispras.ru 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: alex.bennee@linaro.org, pbonzini@redhat.com, pavel.dovgalyuk@ispras.ru Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Record/replay provides REPLAY_CLOCK_LOCKED macro to access the clock when vm_clock_seqlock is locked. This macro is needed because replay internals operate icount. In locked case replay use icount_get_raw_locked for icount request, which prevents excess locking which leads to deadlock. But previously only record code used *_locked function and replay did not. Therefore sometimes clock access lead to deadlocks. This patch fixes clock access for replay too and uses *_locked icount access function. Signed-off-by: Pavel Dovgalyuk --- include/sysemu/replay.h | 14 ++++++++------ replay/replay-internal.c | 29 +++++++++++++++++++++++++---- replay/replay-time.c | 4 ++-- replay/replay.c | 23 +---------------------- stubs/replay-tools.c | 2 +- 5 files changed, 37 insertions(+), 35 deletions(-) diff --git a/include/sysemu/replay.h b/include/sysemu/replay.h index 56c0c17c30..0f3b0f7eac 100644 --- a/include/sysemu/replay.h +++ b/include/sysemu/replay.h @@ -128,18 +128,20 @@ bool replay_has_interrupt(void); int64_t replay_save_clock(ReplayClockKind kind, int64_t clock, int64_t raw_icount); /*! Read the specified clock from the log or return cached data */ -int64_t replay_read_clock(ReplayClockKind kind); +int64_t replay_read_clock(ReplayClockKind kind, int64_t raw_icount); /*! Saves or reads the clock depending on the current replay mode. */ #define REPLAY_CLOCK(clock, value) \ - (replay_mode == REPLAY_MODE_PLAY ? replay_read_clock((clock)) \ + (replay_mode == REPLAY_MODE_PLAY \ + ? replay_read_clock((clock), icount_get_raw()) \ : replay_mode == REPLAY_MODE_RECORD \ - ? replay_save_clock((clock), (value), icount_get_raw()) \ - : (value)) + ? replay_save_clock((clock), (value), icount_get_raw()) \ + : (value)) #define REPLAY_CLOCK_LOCKED(clock, value) \ - (replay_mode == REPLAY_MODE_PLAY ? replay_read_clock((clock)) \ + (replay_mode == REPLAY_MODE_PLAY \ + ? replay_read_clock((clock), icount_get_raw_locked()) \ : replay_mode == REPLAY_MODE_RECORD \ ? replay_save_clock((clock), (value), icount_get_raw_locked()) \ - : (value)) + : (value)) /* Processing data from random generators */ diff --git a/replay/replay-internal.c b/replay/replay-internal.c index 2e8a3e947a..77d0c82327 100644 --- a/replay/replay-internal.c +++ b/replay/replay-internal.c @@ -247,10 +247,31 @@ void replay_advance_current_icount(uint64_t current_icount) /* Time can only go forward */ assert(diff >= 0); - if (diff > 0) { - replay_put_event(EVENT_INSTRUCTION); - replay_put_dword(diff); - replay_state.current_icount += diff; + if (replay_mode == REPLAY_MODE_RECORD) { + if (diff > 0) { + replay_put_event(EVENT_INSTRUCTION); + replay_put_dword(diff); + replay_state.current_icount += diff; + } + } else if (replay_mode == REPLAY_MODE_PLAY) { + if (diff > 0) { + replay_state.instruction_count -= diff; + replay_state.current_icount += diff; + if (replay_state.instruction_count == 0) { + assert(replay_state.data_kind == EVENT_INSTRUCTION); + replay_finish_event(); + /* Wake up iothread. This is required because + timers will not expire until clock counters + 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)); + } } } diff --git a/replay/replay-time.c b/replay/replay-time.c index 43357c9f24..00ebcb7a49 100644 --- a/replay/replay-time.c +++ b/replay/replay-time.c @@ -46,12 +46,12 @@ void replay_read_next_clock(ReplayClockKind kind) } /*! Reads next clock event from the input. */ -int64_t replay_read_clock(ReplayClockKind kind) +int64_t replay_read_clock(ReplayClockKind kind, int64_t raw_icount) { int64_t ret; g_assert(replay_file && replay_mutex_locked()); - replay_account_executed_instructions(); + replay_advance_current_icount(raw_icount); if (replay_next_event_is(EVENT_CLOCK + kind)) { replay_read_next_clock(kind); diff --git a/replay/replay.c b/replay/replay.c index d4c228ab28..c806fec69a 100644 --- a/replay/replay.c +++ b/replay/replay.c @@ -94,28 +94,7 @@ void replay_account_executed_instructions(void) if (replay_mode == REPLAY_MODE_PLAY) { g_assert(replay_mutex_locked()); if (replay_state.instruction_count > 0) { - int count = (int)(replay_get_current_icount() - - replay_state.current_icount); - - /* Time can only go forward */ - assert(count >= 0); - - replay_state.instruction_count -= count; - replay_state.current_icount += count; - if (replay_state.instruction_count == 0) { - assert(replay_state.data_kind == EVENT_INSTRUCTION); - replay_finish_event(); - /* Wake up iothread. This is required because - timers will not expire until clock counters - 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)); - } + replay_advance_current_icount(replay_get_current_icount()); } } } diff --git a/stubs/replay-tools.c b/stubs/replay-tools.c index c06b360e22..43296b3d4e 100644 --- a/stubs/replay-tools.c +++ b/stubs/replay-tools.c @@ -13,7 +13,7 @@ int64_t replay_save_clock(unsigned int kind, int64_t clock, int64_t raw_icount) return 0; } -int64_t replay_read_clock(unsigned int kind) +int64_t replay_read_clock(unsigned int kind, int64_t raw_icount) { abort(); return 0;