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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 00DACC3A59F for ; Thu, 29 Aug 2019 05:38:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C29C2205C9 for ; Thu, 29 Aug 2019 05:38:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726451AbfH2FiZ (ORCPT ); Thu, 29 Aug 2019 01:38:25 -0400 Received: from mga17.intel.com ([192.55.52.151]:42102 "EHLO mga17.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725847AbfH2FiY (ORCPT ); Thu, 29 Aug 2019 01:38:24 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Aug 2019 22:38:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,442,1559545200"; d="scan'208";a="192843631" Received: from araj-mobl1.jf.intel.com ([10.254.101.231]) by orsmga002.jf.intel.com with ESMTP; 28 Aug 2019 22:38:22 -0700 Date: Wed, 28 Aug 2019 22:38:22 -0700 From: "Raj, Ashok" To: Borislav Petkov Cc: Mihai Carabas , Boris Ostrovsky , "H. Peter Anvin" , Ingo Molnar , Jon Grimm , kanth.ghatraju@oracle.com, konrad.wilk@oracle.com, patrick.colp@oracle.com, Thomas Gleixner , Tom Lendacky , x86-ml , linux-kernel@vger.kernel.org, Ashok Raj Subject: Re: [PATCH] x86/microcode: Add an option to reload microcode even if revision is unchanged Message-ID: <20190829053822.GA17646@araj-mobl1.jf.intel.com> References: <1567056803-6640-1-git-send-email-ashok.raj@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1567056803-6640-1-git-send-email-ashok.raj@intel.com> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Boris, sorry i added the wrong message id in the commit log. https://lore.kernel.org/r/20190824085300.GB16813@zn.tnic/ On Wed, Aug 28, 2019 at 10:33:22PM -0700, Ashok Raj wrote: > During microcode development, its often required to test different versions > of microcode. Intel microcode loader enforces loading only if the revision is > greater than what is currently loaded on the cpu. Overriding this behavior > allows us to reuse the same revision during development cycles. > This facilty also allows us to share debug microcode with development > partners for getting feedback before microcode release. > > Microcode developers should have other ways to check which > of their internal version is actually loaded. For e.g. checking a > temporary MSR for instance. In order to reload the same microcode do as > shown below. > > # echo 2 > /sys/devices/system/cpu/microcode/reload > > as root. > > > I tested this on top of the parallel ucode load patch > > https://lore.kernel.org/r/1566506627-16536-2-git-send-email-mihai.carabas@oracle.com/ Please update with the following: https://lore.kernel.org/r/20190824085300.GB16813@zn.tnic/ Cheers, Ashok