From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 00D05C433EF for ; Mon, 24 Jan 2022 08:44:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242387AbiAXIn7 (ORCPT ); Mon, 24 Jan 2022 03:43:59 -0500 Received: from mga09.intel.com ([134.134.136.24]:62624 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242438AbiAXInu (ORCPT ); Mon, 24 Jan 2022 03:43:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1643013830; x=1674549830; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5j5TJCoGxF4CAqoY0fyuwuUeKSolXVQK42ITi5wrZag=; b=d69RjDpPDJuqRSGyW34xyocFm9rinqpfzJnuEKj+S9zZ1VPPY0o8D3CN ar+A2nzhLAmROR6N/FyEser+srJqwMwf0KCS3RVQanvNOqK/i65xwEv0+ YQdZ30aRqQRtJgdBrIh4k8XHlfhO20DVhoABOI05YCBevS0+uty9TUJYS 30+oGRfuh5Tnjw67+7lNEsbr5Bp8ElRq9g8y6aKRex9beMjwX8TJJzKVS SJpz0wLjDCeiXOvtzt+ql00PuWjTgM0O9iFLRVtuH4p2rTypmHCnRrnmn U7QJ6+xLD+4IcJ6W2vzfDjUvl8LuwoJJ5syux7tIcUDCCbDFeVrjcZAt7 g==; X-IronPort-AV: E=McAfee;i="6200,9189,10236"; a="245778524" X-IronPort-AV: E=Sophos;i="5.88,311,1635231600"; d="scan'208";a="245778524" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jan 2022 00:43:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.88,311,1635231600"; d="scan'208";a="627417322" Received: from ahunter-desktop.fi.intel.com ([10.237.72.92]) by orsmga004.jf.intel.com with ESMTP; 24 Jan 2022 00:42:58 -0800 From: Adrian Hunter To: Arnaldo Carvalho de Melo Cc: Jiri Olsa , Alexander Shishkin , Andi Kleen , linux-kernel@vger.kernel.org Subject: [PATCH 25/25] perf intel-pt: Add documentation for Event Trace and TNT disable Date: Mon, 24 Jan 2022 10:42:01 +0200 Message-Id: <20220124084201.2699795-26-adrian.hunter@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220124084201.2699795-1-adrian.hunter@intel.com> References: <20220124084201.2699795-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add documentation for Event Trace and TNT disable to the perf Intel PT man page. Signed-off-by: Adrian Hunter --- tools/perf/Documentation/perf-intel-pt.txt | 104 ++++++++++++++++++++- 1 file changed, 102 insertions(+), 2 deletions(-) diff --git a/tools/perf/Documentation/perf-intel-pt.txt b/tools/perf/Documentation/perf-intel-pt.txt index cbb920f5d056..ff58bd4c381b 100644 --- a/tools/perf/Documentation/perf-intel-pt.txt +++ b/tools/perf/Documentation/perf-intel-pt.txt @@ -108,9 +108,10 @@ displayed as follows: perf script --itrace=ibxwpe -F+flags -The flags are "bcrosyiABExgh" which stand for branch, call, return, conditional, +The flags are "bcrosyiABExghDt" which stand for branch, call, return, conditional, system, asynchronous, interrupt, transaction abort, trace begin, trace end, -in transaction, VM-entry, and VM-exit respectively. +in transaction, VM-entry, VM-exit, interrupt disabled, and interrupt disable +toggle respectively. perf script also supports higher level ways to dump instruction traces: @@ -483,6 +484,30 @@ pwr_evt Enable power events. The power events provide information about which contains "1" if the feature is supported and "0" otherwise. +event Enable Event Trace. The events provide information about asynchronous + events. + + Support for this feature is indicated by: + + /sys/bus/event_source/devices/intel_pt/caps/event_trace + + which contains "1" if the feature is supported and + "0" otherwise. + +notnt Disable TNT packets. Without TNT packets, it is not possible to walk + executable code to reconstruct control flow, however FUP, TIP, TIP.PGE + and TIP.PGD packets still indicate asynchronous control flow, and (if + return compression is disabled - see noretcomp) return statements. + The advantage of eliminating TNT packets is reducing the size of the + trace and corresponding tracing overhead. + + Support for this feature is indicated by: + + /sys/bus/event_source/devices/intel_pt/caps/tnt_disable + + which contains "1" if the feature is supported and + "0" otherwise. + AUX area sampling option ~~~~~~~~~~~~~~~~~~~~~~~~ @@ -876,6 +901,8 @@ The letters are: p synthesize "power" events (incl. PSB events) c synthesize branches events (calls only) r synthesize branches events (returns only) + o synthesize PEBS-via-PT events + I synthesize Event Trace events e synthesize tracing error events d create a debug log g synthesize a call chain (use with i or x) @@ -1371,6 +1398,79 @@ There were none. :17006 17006 [001] 11500.262869216: ffffffff8220116e error_entry+0xe ([guest.kernel.kallsyms]) pushq %rax +Event Trace +----------- + +Event Trace records information about asynchronous events, for example interrupts, +faults, VM exits and entries. The information is recorded in CFE and EVD packets, +and also the Interrupt Flag is recorded on the MODE.Exec packet. The CFE packet +contains a type field to identify one of the following: + + 1 INTR interrupt, fault, exception, NMI + 2 IRET interrupt return + 3 SMI system management interrupt + 4 RSM resume from system management mode + 5 SIPI startup interprocessor interrupt + 6 INIT INIT signal + 7 VMENTRY VM-Entry + 8 VMEXIT VM-Entry + 9 VMEXIT_INTR VM-Exit due to interrupt + 10 SHUTDOWN Shutdown + +For more details, refer to the Intel 64 and IA-32 Architectures Software +Developer Manuals (version 076 or later). + +The capability to do Event Trace is indicated by the +/sys/bus/event_source/devices/intel_pt/caps/event_trace file. + +Event trace is selected for recording using the "event" config term. e.g. + + perf record -e intel_pt/event/u uname + +Event trace events are output using the --itrace I option. e.g. + + perf script --itrace=Ie + +perf script displays events containing CFE type, vector and event data, +in the form: + + evt: hw int (t) cfe: INTR IP: 1 vector: 3 PFA: 0x8877665544332211 + +The IP flag indicates if the event binds to an IP, which includes any case where +flow control packet generation is enabled, as well as when CFE packet IP bit is +set. + +perf script displays events containing changes to the Interrupt Flag in the form: + + iflag: t IFLAG: 1->0 via branch + +where "via branch" indicates a branch (interrupt or return from interrupt) and +"non branch" indicates an instruction such as CFI, STI or POPF). + +In addition, the current state of the interrupt flag is indicated by the presence +or absence of the "D" (interrupt disabled) perf script flag. If the interrupt +flag is changed, then the "t" flag is also included i.e. + + no flag, interrupts enabled IF=1 + t interrupts become disabled IF=1 -> IF=0 + D interrupts are disabled IF=0 + Dt interrupts become enabled IF=0 -> IF=1 + +The intel-pt-events.py script illustrates how to access Event Trace information +using a Python script. + + +TNT Disable +----------- + +TNT packets are disabled using the "notnt" config term. e.g. + + perf record -e intel_pt/notnt/u uname + +In that case the --itrace q option is forced because walking executable code +to reconstruct the control flow is not possible. + + SEE ALSO -------- -- 2.25.1