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 2CC7BC77B72 for ; Mon, 17 Apr 2023 11:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230197AbjDQLtY (ORCPT ); Mon, 17 Apr 2023 07:49:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39064 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230036AbjDQLtV (ORCPT ); Mon, 17 Apr 2023 07:49:21 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 69D575FD0; Mon, 17 Apr 2023 04:48:24 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2CBD71063; Mon, 17 Apr 2023 04:22:47 -0700 (PDT) Received: from [10.57.80.202] (unknown [10.57.80.202]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 858853F6C4; Mon, 17 Apr 2023 04:22:02 -0700 (PDT) Message-ID: <6a775920-9260-f82e-dace-0b792f5371c4@arm.com> Date: Mon, 17 Apr 2023 12:21:58 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:102.0) Gecko/20100101 Thunderbird/102.10.0 Subject: Re: [regression] Bug 217218 - Trying to boot Linux version 6-2.2 kernel with Marvell SATA controller 88SE9235 Content-Language: en-GB To: Christoph Hellwig Cc: Linux regressions mailing list , LKML , Linux PCI , iommu@lists.linux.dev, baolu.lu@linux.intel.com References: <20230328012231.GB21977@lst.de> <01c50370-002d-5e18-3edc-81c9527aedc9@arm.com> <20230416064156.GA6410@lst.de> From: Robin Murphy In-Reply-To: <20230416064156.GA6410@lst.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023-04-16 07:41, Christoph Hellwig wrote: > On Thu, Mar 30, 2023 at 01:18:45PM +0100, Robin Murphy wrote: >> FWIW "Marvell SATA" instantly makes me suspect the phantom function quirk. >> What *should* happen is the IOMMU driver sees the PCI DMA aliases correctly >> and sets up context entries for both 07.00.0 and 07.00.1, but it looks like >> that may be what's gone awry. > > Looking at the bug report it seems this is device 9235, which doesn't > need the DMA alias quirks. Indeed that one doesn't appear to be in the quirk list currently. However the symptom of DMA traffic from function 1 which the IOMMU clearly wasn't expecting firmly suggests that it *does* need the quirk. Digging up the original report, the lspci output there suggests that 07:00.1 isn't a real function, which would further confirm it. The other thing which catches my interest is the seemingly-conflicting "iommu=soft" and "intel_iommu=on" arguments - I could well believe that refactoring the x86 IOMMU detection stuff might have subtly changed the interaction there, such that previously it ended up not actually using the IOMMU for DMA ops, but now it is? Robin.