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=-5.5 required=3.0 tests=BAYES_00, 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 9140CC433E2 for ; Wed, 22 Jul 2020 12:49:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73DC2206E3 for ; Wed, 22 Jul 2020 12:49:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732154AbgGVMtA (ORCPT ); Wed, 22 Jul 2020 08:49:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35986 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726161AbgGVMs7 (ORCPT ); Wed, 22 Jul 2020 08:48:59 -0400 Received: from theia.8bytes.org (8bytes.org [IPv6:2a01:238:4383:600:38bc:a715:4b6d:a889]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FB65C0619DC; Wed, 22 Jul 2020 05:48:59 -0700 (PDT) Received: by theia.8bytes.org (Postfix, from userid 1000) id 682032C8; Wed, 22 Jul 2020 14:48:56 +0200 (CEST) Date: Wed, 22 Jul 2020 14:48:55 +0200 From: Joerg Roedel To: Robin Murphy Cc: hch@lst.de, iommu@lists.linux-foundation.org, jonathan.lemon@gmail.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, baolu.lu@linux.intel.com, dwmw2@infradead.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 2/2] iommu/dma: Avoid SAC address trick for PCIe devices Message-ID: <20200722124854.GZ27672@8bytes.org> References: <20200713131426.GQ27672@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Jul 14, 2020 at 12:42:36PM +0100, Robin Murphy wrote: > Oh bother - yes, this could have been masking all manner of bugs. That > system will presumably also break if you managed to exhaust the 32-bit IOVA > space such that the allocator moved up to the higher range anyway, or if you > passed the XHCI through to a VM with a sufficiently wacky GPA layout, but I > guess those are cases that simply nobody's run into yet. > > Does the firmware actually report any upper address constraint such that > Sebastian's IVRS aperture patches might help? No, it doesn't. I am not sure what the best way is to get these issues found and fixed. I doubt they will be getting fixed when the allocation pattern isn't changed, maybe we can put your changes behind a config variable and start testing/reporting bugs/etc. Regards, Joerg