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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 7EA47C433B4 for ; Wed, 19 May 2021 08:11:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F8F461007 for ; Wed, 19 May 2021 08:11:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237618AbhESIMj (ORCPT ); Wed, 19 May 2021 04:12:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:49860 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237518AbhESIMj (ORCPT ); Wed, 19 May 2021 04:12:39 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 00900610A2; Wed, 19 May 2021 08:11:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621411880; bh=/zr0PHowEjmcA1VKWh07Xdh5ZlxoJOTHc9TqGLD1VR4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QD3TDsCOON4lkKSYmseoPt+5K0iJR3e5rrDxfcWszHPSBrBJEEpZD9F9vfV9DNqOw 89U86bha6xgzF8Pw6qX3gwfnVYEfrPOBIUtb8uNIF/jCuy6rCjEd0HT4fbNfluNIYh YWbqMxUyGFbmSoIl6iIABWxG1/JLlVp1zWQOwiw8= Date: Wed, 19 May 2021 10:11:18 +0200 From: Greg KH To: Jianxiong Gao Cc: stable@vger.kernel.org, hch@lst.de, marcorr@google.com, sashal@kernel.org Subject: Re: [PATCH 5.4 v2 0/9] preserve DMA offsets when using swiotlb Message-ID: References: <20210518221818.2963918-1-jxgao@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210518221818.2963918-1-jxgao@google.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Tue, May 18, 2021 at 10:18:09PM +0000, Jianxiong Gao wrote: > We observed several NVMe failures when running with SWIOTLB. The root > cause of the issue is that when data is mapped via SWIOTLB, the address > offset is not preserved. Several device drivers including the NVMe > driver relies on this offset to function correctly. > > Even though we discovered the error when running using AMD SEV, we have > reproduced the same error in Rhel 8 without SEV. By adding swiotlb=force > option to the boot command line parameter, NVMe funcionality is > impacted. For example formatting a disk into xfs format returns an > error. I still fail to understand why you can not just use the 5.10.y kernel or newer. What is preventing you from doing this if you wish to use this type of hardware? This is not a "regression" in that the 5.4.y kernel has never worked with this hardware before, it feels like a new feature. Please, just use 5.10.y or newer, your life will be so much easier in the longrun. thanks, greg k-h