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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 1A4F3C282CC for ; Mon, 4 Feb 2019 20:38:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DAB432175B for ; Mon, 4 Feb 2019 20:38:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728990AbfBDUiB (ORCPT ); Mon, 4 Feb 2019 15:38:01 -0500 Received: from mga04.intel.com ([192.55.52.120]:41613 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726676AbfBDUiB (ORCPT ); Mon, 4 Feb 2019 15:38:01 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 04 Feb 2019 12:38:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.56,560,1539673200"; d="scan'208";a="144143968" Received: from linux.intel.com ([10.54.29.200]) by fmsmga001.fm.intel.com with ESMTP; 04 Feb 2019 12:38:00 -0800 Received: from [10.254.84.37] (kliang2-mobl1.ccr.corp.intel.com [10.254.84.37]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by linux.intel.com (Postfix) with ESMTPS id 9A2FE58044E; Mon, 4 Feb 2019 12:37:59 -0800 (PST) Subject: Re: [PATCH V6 2/5] perf/x86/kvm: Avoid unnecessary work in guest filtering To: Borislav Petkov Cc: Peter Zijlstra , x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, ak@linux.intel.com, eranian@google.com References: <1548106951-4811-1-git-send-email-kan.liang@linux.intel.com> <1548106951-4811-2-git-send-email-kan.liang@linux.intel.com> <20190204153827.GG17528@hirez.programming.kicks-ass.net> <20190204154411.GC17582@hirez.programming.kicks-ass.net> <90e071c0-cdf4-3a31-4e44-2c5b84af5fa3@linux.intel.com> <20190204162312.GJ17528@hirez.programming.kicks-ass.net> <2c429bbd-00fb-2e3a-7d58-27123400b722@linux.intel.com> <20190204181504.GH29639@zn.tnic> <134894ac-a43b-7ec7-f313-b5d8de357a7e@linux.intel.com> <20190204194306.GI29639@zn.tnic> From: "Liang, Kan" Message-ID: <12e3f6d3-0186-a540-7feb-778f4d78c8cf@linux.intel.com> Date: Mon, 4 Feb 2019 15:37:58 -0500 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.5.0 MIME-Version: 1.0 In-Reply-To: <20190204194306.GI29639@zn.tnic> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2/4/2019 2:43 PM, Borislav Petkov wrote: > On Mon, Feb 04, 2019 at 01:57:49PM -0500, Liang, Kan wrote: >> You mean a given microcode revision X applying to multiple stepping, >> right? > > Yes, the range thing. You specify a range of steppings: > > kabylake mobile with steppings 9-12 > kabylake desktop with steppings 10-13 > >> I don't think so. I still think the KABYLAKE case is an uncommon case. > > You mean it is uncommon because there are already *two* models which > need it or because this is only kabylake and it won't happen in the > future? The latter. As you can see in the patch series, for other platforms (from core to atom), the microcode revision is always different on different stepping of the same model. I believe the kabylake thing is one off. > >> Can we do something as below just for this case? > > Of course not. _FOUR is just silly and if a *fifth* stepping appears, > you need to go fixup again. > > If anything and if this kabylake thing is one off, I'd prefer we keep it > as is. > OK. I will keep it as is on V7. Thanks, Kan