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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_NEOMUTT 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 43A2FC282D7 for ; Wed, 30 Jan 2019 16:24:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1CA53218A4 for ; Wed, 30 Jan 2019 16:24:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730905AbfA3QYg (ORCPT ); Wed, 30 Jan 2019 11:24:36 -0500 Received: from 8bytes.org ([81.169.241.247]:35954 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725808AbfA3QYg (ORCPT ); Wed, 30 Jan 2019 11:24:36 -0500 Received: by theia.8bytes.org (Postfix, from userid 1000) id C42D15B8; Wed, 30 Jan 2019 17:24:34 +0100 (CET) Date: Wed, 30 Jan 2019 17:24:33 +0100 From: Joerg Roedel To: Lu Baolu Cc: David Woodhouse , ashok.raj@intel.com, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Liu Yi L , Jacob Pan Subject: Re: [PATCH 1/1] iommu/vt-d: Leave scalable mode default off Message-ID: <20190130162433.ac3gzibnurwgubzf@8bytes.org> References: <20190124023132.20410-1-baolu.lu@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190124023132.20410-1-baolu.lu@linux.intel.com> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 24, 2019 at 10:31:32AM +0800, Lu Baolu wrote: > Commit 765b6a98c1de3 ("iommu/vt-d: Enumerate the scalable > mode capability") enables VT-d scalable mode if hardware > advertises the capability. As we will bring up different > features and use cases to upstream in different patch > series, it will leave some intermediate kernel versions > which support partial features. Hence, end user might run > into problems when they use such kernels on bare metals > or virtualization environments. > > This leaves scalable mode default off and end users could > turn it on with "intel-iommu=sm_on" only when they have > clear ideas about which scalable features are supported > in the kernel. > > Cc: Liu Yi L > Cc: Jacob Pan > Suggested-by: Ashok Raj > Suggested-by: Kevin Tian > Signed-off-by: Lu Baolu Applied to iommu/fixes, thanks.