From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from 8bytes.org ([81.169.241.247]:56861 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932887AbbI2QUn (ORCPT ); Tue, 29 Sep 2015 12:20:43 -0400 Date: Tue, 29 Sep 2015 18:20:42 +0200 From: Joerg Roedel To: Mikulas Patocka Cc: Andreas Hartmann , iommu@lists.linux-foundation.org, Leo Duran , Christoph Hellwig , device-mapper development , Milan Broz , Jens Axboe , linux-pci , Linus Torvalds Subject: Re: [dm-devel] AMD-Vi IO_PAGE_FAULTs and ata3.00: failed command: READ FPDMA QUEUED errors since Linux 4.0 Message-ID: <20150929162042.GR3036@8bytes.org> References: <55B7BEA2.30205@01019freenet.de> <20150728175054.GB24782@redhat.com> <55B7D054.4070308@maya.org> <20150728192908.GA25264@redhat.com> <55BCD5A7.2080708@maya.org> <55BE1D5E.6020709@maya.org> <55FE5740.2060701@maya.org> <20150929152100.GL3036@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-pci-owner@vger.kernel.org List-ID: On Tue, Sep 29, 2015 at 11:58:10AM -0400, Mikulas Patocka wrote: > On Tue, 29 Sep 2015, Joerg Roedel wrote: > There was a patch (34b48db66e08ca1c1bc07cf305d672ac940268dc) that > increased default block request size. That patch triggers AMD-Vi page > faults. The bug may be in ATA driver, in ATA controller on in AMD-Vi > driver or hardware. I didn't see anything in that thread that proves that > the bug in not in AMD-Vi IOMMU. > > The bug probably existed even before kernel 3.19, but it was masked by the > fact that I/O request size was artifically capped. Bisecting probably > won't find it, as it may have existed since ever. Okay, I see. But as long as the request-size is not bigger than 128MB (the biggest chunk the AMD IOMMU driver can map at once), I don't see how the IOMMU driver could be at fault. Which ATA driver is in use when this happens and are there instructions on how to reproduce the issue? Alternativly someone who can reproduce it should trace the calls to __map_single and __unmap_single in the AMD IOMMU driver to find out whether the addresses which the faults happen on are really mapped, or at least requested from the AMD IOMMU driver. Joerg