From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754038AbbAEPlA (ORCPT ); Mon, 5 Jan 2015 10:41:00 -0500 Received: from fortimail.online.lv ([81.198.164.220]:36840 "EHLO fortimail.online.lv" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753348AbbAEPk7 (ORCPT ); Mon, 5 Jan 2015 10:40:59 -0500 X-Greylist: delayed 930 seconds by postgrey-1.27 at vger.kernel.org; Mon, 05 Jan 2015 10:40:58 EST Message-ID: <54AAACE5.2020909@apollo.lv> Date: Mon, 05 Jan 2015 17:25:25 +0200 From: Raimonds Cicans User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Question about: AMD-Vi: Event logged [IO_PAGE_FAULT ... Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit DomainKey-Status: no signature DKIM-Status: no signature X-AXIGEN-DK-Result: No records X-AXIGEN-DKIM-Result: No records Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello. After kernel upgrade (3.13 => 3.17) I started to receive following string in my logs: AMD-Vi: Event logged [IO_PAGE_FAULT device=08:00.0 domain=0x001c address=0x0000000001355000 flags=0x0000] I would like to deeper understand this problem, so it would be nice if some body can fix my assumptions and answer my questions. Assumptions: 1) This message is generated by AMD IOMMU subsystem because PCIe device 08:00.0 tried to access memory region which was not mapped to any real memory (lspci show that this device is DVB-S2 receiver card TBS 6981) 2) Because flags are 0 and because in general receivers write to memory not read from memory it is memory write operation 3) Possible causes: a) memory region was never mapped b) device accessed memory region before it was mapped c) device accessed memory region after it was unmapped 3) Suspects: a) kernel's DMA subsystem: very unlikely b) kernel's IOMMU subsystem: very unlikely c) AMD IOMMU driver: unlikely? - i had problems with AMD IOMMU itself in kernels 3.14 - 3.17 (AMD-Vi: Completion-Wait loop timed out) So maybe this problem not fully fixed? d) Receiver's driver: likely Questions: 1) What 'domain=0x001c' mean? 2) Where I can find definition of possible flags? 3) What kind of address is written in message? - physical? - virtual? - address from devices point of view? Thank you. Raimonds Cicans