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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2AD03E81DF5 for ; Fri, 6 Oct 2023 13:02:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231905AbjJFNCz (ORCPT ); Fri, 6 Oct 2023 09:02:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232469AbjJFNCg (ORCPT ); Fri, 6 Oct 2023 09:02:36 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1C58A18B; Fri, 6 Oct 2023 06:02:28 -0700 (PDT) Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4S27qm2Qp6z6K6wd; Fri, 6 Oct 2023 21:02:12 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Fri, 6 Oct 2023 14:02:25 +0100 Date: Fri, 6 Oct 2023 14:02:24 +0100 From: Jonathan Cameron To: David Rientjes CC: Jiaqi Yan , "Luck, Tony" , "Grimm, Jon" , , , , , , , , , , , , , , , , , , , , , Subject: Re: [RFC PATCH 2/9] memory: scrub: sysfs: Add Documentation entries for set of scrub attributes Message-ID: <20231006140224.000018a2@Huawei.com> In-Reply-To: <92f48c1c-3235-49b2-aabd-7da87ad3febc@google.com> References: <20230915172818.761-1-shiju.jose@huawei.com> <20230915172818.761-3-shiju.jose@huawei.com> <20230922111740.000046d7@huawei.com> <92f48c1c-3235-49b2-aabd-7da87ad3febc@google.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 4 Oct 2023 20:18:12 -0700 (PDT) David Rientjes wrote: > On Wed, 27 Sep 2023, Jiaqi Yan wrote: > > > > > 1. I am not aware of any chip/platform hardware that implemented the > > > > hw ps part defined in ACPI RASF/RAS2 spec. So I am curious what the > > > > RAS experts from different hardware vendors think about this. For > > > > example, Tony and Dave from Intel, Jon and Vilas from AMD. Is there > > > > any hardware platform (if allowed to disclose) that implemented ACPI > > > > RASF/RAS2? If so, will vendors continue to support the control of > > > > patrol scrubber using the ACPI spec? If not (as Tony said in [1], will > > > > the vendor consider starting some future platform? > > > > > > > > If we are unlikely to get the vendor support, creating this ACPI > > > > specific sysfs API (and the driver implementations) in Linux seems to > > > > have limited meaning. > > > > > > There is a bit of a chicken and egg problem here. Until there is > > > reasonable support in kernel (or it looks like there will be), > > > BIOS teams push back on a requirement to add the tables. > > > I'd encourage no one to bother with RASF - RAS2 is much less > > > ambiguous. > > > > Here mainly to re-ping folks from Intel (Tony and Dave) and AMD (Jon > > and Vilas) for your opinion on RAS2. > > > > We'll need to know from vendors, ideally at minimum from both Intel and > AMD, whether RAS2 is the long-term vision here. Nothing is set in stone, > of course, but deciding whether RAS2 is the standard that we should be > rallying around will help to guide future development including in the > kernel. > > If RAS2 is insufficient for future use cases or we would need to support > multiple implementations in the kernel for configuring the patrol scrubber > depending on vendor, that's great feedback to have. > > I'd much rather focus on implementing something in the kernel that we have > some clarity about the vendors supporting, especially when it comes with > user visible interfaces, as opposed to something that may not be used long > term. I think that's a fair ask and that vendor feedback is required > here? Agreed and happy to have feedback from Intel and AMD + all the other CPU vendors who make use of ACPI + all the OEMs who add stuff well beyond what Intel and AMD tell them to :) I'll just note a lot of the ACPI support in the kernel covers stuff not used on mainstream x86 platforms because they are doing something custom and we didn't want 2 + X custom implementations... Some other interfaces for scrub control (beyond existing embedded ones) will surface in the next few months where RAS2 is not appropriate. Jonathan