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 X-Spam-Level: X-Spam-Status: No, score=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F3FD6C31E44 for ; Fri, 14 Jun 2019 11:28:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D3FF1208CA for ; Fri, 14 Jun 2019 11:28:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727527AbfFNL25 (ORCPT ); Fri, 14 Jun 2019 07:28:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57640 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727262AbfFNL25 (ORCPT ); Fri, 14 Jun 2019 07:28:57 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A3AB3356C4; Fri, 14 Jun 2019 11:28:56 +0000 (UTC) Received: from krava (ovpn-204-154.brq.redhat.com [10.40.204.154]) by smtp.corp.redhat.com (Postfix) with SMTP id 8F0EC6103B; Fri, 14 Jun 2019 11:28:54 +0000 (UTC) Date: Fri, 14 Jun 2019 13:28:53 +0200 From: Jiri Olsa To: Peter Zijlstra , Kan Liang Cc: Jiri Olsa , David Carrillo-Cisneros , Arnaldo Carvalho de Melo , lkml , Ingo Molnar , Namhyung Kim , Alexander Shishkin , Andi Kleen , Tom Vaden Subject: [RFC] perf/x86/intel: Disable check_msr for real hw Message-ID: <20190614112853.GC4325@krava> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.11.4 (2019-03-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Fri, 14 Jun 2019 11:28:56 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org hi, the HPE server can do POST tracing and have enabled LBR tracing during the boot, which makes check_msr fail falsly. It looks like check_msr code was added only to check on guests MSR access, would it be then ok to disable check_msr for real hardware? (as in patch below) We could also check if LBR tracing is enabled and make appropriate checks, but this change is simpler ;-) ideas? thanks, jirka --- arch/x86/events/intel/core.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c index 71001f005bfe..1194ae7e1992 100644 --- a/arch/x86/events/intel/core.c +++ b/arch/x86/events/intel/core.c @@ -20,6 +20,7 @@ #include #include #include +#include #include "../perf_event.h" @@ -4050,6 +4051,13 @@ static bool check_msr(unsigned long msr, u64 mask) { u64 val_old, val_new, val_tmp; + /* + * Disable the check for real HW, so we don't + * mess up with potentionaly enabled regs. + */ + if (hypervisor_is_type(X86_HYPER_NATIVE)) + return true; + /* * Read the current value, change it and read it back to see if it * matches, this is needed to detect certain hardware emulators -- 2.21.0