From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932389AbcDFMJm (ORCPT ); Wed, 6 Apr 2016 08:09:42 -0400 Received: from mga03.intel.com ([134.134.136.65]:31536 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932245AbcDFMJk (ORCPT ); Wed, 6 Apr 2016 08:09:40 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,447,1455004800"; d="scan'208";a="681715863" From: Alexander Shishkin To: Borislav Petkov , Peter Zijlstra Cc: Gleb Natapov , Paolo Bonzini , x86@kernel.org, kvm@vger.kernel.org, Ingo Molnar , linux-kernel@vger.kernel.org, tglx@linutronix.de, hpa@zytor.com, Arnaldo Carvalho de Melo Subject: Re: [PATCH] perf/x86/intel/pt: Don't die on VMXON In-Reply-To: <20160406115516.GE12070@pd.tnic> References: <1459527854-5899-1-git-send-email-alexander.shishkin@linux.intel.com> <20160406085227.GO3448@twins.programming.kicks-ass.net> <87vb3v56x2.fsf@ashishki-desk.ger.corp.intel.com> <20160406115215.GK2906@worktop> <20160406115516.GE12070@pd.tnic> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-pc-linux-gnu) Date: Wed, 06 Apr 2016 15:07:48 +0300 Message-ID: <874mbfym7f.fsf@ashishki-desk.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Borislav Petkov writes: > On Wed, Apr 06, 2016 at 01:52:15PM +0200, Peter Zijlstra wrote: >> Borislav tells me this ought to be boot_cpu_has(X86_FEATURE_VMX) >> >> > + /* Intel SDM, 36.5 "Tracing post-VMXON" */ >> > + rdmsrl(MSR_IA32_VMX_MISC, reg); >> > + if (reg & BIT(14)) > > Also, I needz to consult my crystal ball about what bit 14 is... > > :-) I know. It's right there in SDM chapter 36.5, referred to as "bit 14" and it's not mentioned anywhere else that I could find, so I just left a comment there. Regards, -- Alex