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=-0.8 required=3.0 tests=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 606CBC3A5A2 for ; Tue, 3 Sep 2019 07:41:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 32A5022DBF for ; Tue, 3 Sep 2019 07:41:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727969AbfICHls (ORCPT ); Tue, 3 Sep 2019 03:41:48 -0400 Received: from mga02.intel.com ([134.134.136.20]:5585 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725895AbfICHls (ORCPT ); Tue, 3 Sep 2019 03:41:48 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2019 00:41:47 -0700 X-IronPort-AV: E=Sophos;i="5.64,462,1559545200"; d="scan'208";a="176505229" Received: from jkrzyszt-desk.igk.intel.com (HELO jkrzyszt-desk.ger.corp.intel.com) ([172.22.244.17]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2019 00:41:45 -0700 From: Janusz Krzysztofik To: Lu Baolu Cc: David Woodhouse , Joerg Roedel , iommu@lists.linux-foundation.org, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, =?utf-8?B?TWljaGHFgg==?= Wajdeczko , Janusz Krzysztofik Subject: Re: [RFC PATCH] iommu/vt-d: Fix IOMMU field not populated on device hot re-plug Date: Tue, 03 Sep 2019 09:41:23 +0200 Message-ID: <2674326.ZPvzKFr69O@jkrzyszt-desk.ger.corp.intel.com> Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 In-Reply-To: <52fbfac9-c879-4b45-dd74-fafe62c2432b@linux.intel.com> References: <20190822142922.31526-1-janusz.krzysztofik@linux.intel.com> <1769080.0GM3UzqXcv@jkrzyszt-desk.ger.corp.intel.com> <52fbfac9-c879-4b45-dd74-fafe62c2432b@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Baolu, On Tuesday, September 3, 2019 3:29:40 AM CEST Lu Baolu wrote: > Hi Janusz, > > On 9/2/19 4:37 PM, Janusz Krzysztofik wrote: > >> I am not saying that keeping data is not acceptable. I just want to > >> check whether there are any other solutions. > > Then reverting 458b7c8e0dde and applying this patch still resolves the issue > > for me. No errors appear when mappings are unmapped on device close after the > > device has been removed, and domain info preserved on device removal is > > successfully reused on device re-plug. > > This patch doesn't look good to me although I agree that keeping data is > acceptable. It updates dev->archdata.iommu, but leaves the hardware > context/pasid table unchanged. This might cause problems somewhere. > > > > > Is there anything else I can do to help? > > Can you please tell me how to reproduce the problem? The most simple way to reproduce the issue, assuming there are no non-Intel graphics adapters installed, is to run the following shell commands: #!/bin/sh # load i915 module modprobe i915 # open an i915 device and keep it open in background cat /dev/dri/card0 >/dev/null & sleep 2 # simulate device unplug echo 1 >/sys/class/drm/card0/device/remove # make the background process close the device on exit kill $! Thanks, Janusz > Keeping the per > device domain info while device is unplugged is a bit dangerous because > info->dev might be a wild pointer. We need to work out a clean fix. > > > > > Thanks, > > Janusz > > > > Best regards, > Baolu > 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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 340E7C3A5A2 for ; Tue, 3 Sep 2019 07:41:51 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1379922DBF for ; Tue, 3 Sep 2019 07:41:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1379922DBF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id CF2D4CA1; Tue, 3 Sep 2019 07:41:50 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 9C352C9E for ; Tue, 3 Sep 2019 07:41:49 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 91AE3709 for ; Tue, 3 Sep 2019 07:41:48 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2019 00:41:48 -0700 X-IronPort-AV: E=Sophos;i="5.64,462,1559545200"; d="scan'208";a="176505229" Received: from jkrzyszt-desk.igk.intel.com (HELO jkrzyszt-desk.ger.corp.intel.com) ([172.22.244.17]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Sep 2019 00:41:45 -0700 From: Janusz Krzysztofik To: Lu Baolu Subject: Re: [RFC PATCH] iommu/vt-d: Fix IOMMU field not populated on device hot re-plug Date: Tue, 03 Sep 2019 09:41:23 +0200 Message-ID: <2674326.ZPvzKFr69O@jkrzyszt-desk.ger.corp.intel.com> Organization: Intel Technology Poland sp. z o.o. - ul. Slowackiego 173, 80-298 Gdansk - KRS 101882 - NIP 957-07-52-316 In-Reply-To: <52fbfac9-c879-4b45-dd74-fafe62c2432b@linux.intel.com> References: <20190822142922.31526-1-janusz.krzysztofik@linux.intel.com> <1769080.0GM3UzqXcv@jkrzyszt-desk.ger.corp.intel.com> <52fbfac9-c879-4b45-dd74-fafe62c2432b@linux.intel.com> MIME-Version: 1.0 Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Janusz Krzysztofik , David Woodhouse , intel-gfx@lists.freedesktop.org, =?utf-8?B?TWljaGHFgg==?= Wajdeczko X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Hi Baolu, On Tuesday, September 3, 2019 3:29:40 AM CEST Lu Baolu wrote: > Hi Janusz, > > On 9/2/19 4:37 PM, Janusz Krzysztofik wrote: > >> I am not saying that keeping data is not acceptable. I just want to > >> check whether there are any other solutions. > > Then reverting 458b7c8e0dde and applying this patch still resolves the issue > > for me. No errors appear when mappings are unmapped on device close after the > > device has been removed, and domain info preserved on device removal is > > successfully reused on device re-plug. > > This patch doesn't look good to me although I agree that keeping data is > acceptable. It updates dev->archdata.iommu, but leaves the hardware > context/pasid table unchanged. This might cause problems somewhere. > > > > > Is there anything else I can do to help? > > Can you please tell me how to reproduce the problem? The most simple way to reproduce the issue, assuming there are no non-Intel graphics adapters installed, is to run the following shell commands: #!/bin/sh # load i915 module modprobe i915 # open an i915 device and keep it open in background cat /dev/dri/card0 >/dev/null & sleep 2 # simulate device unplug echo 1 >/sys/class/drm/card0/device/remove # make the background process close the device on exit kill $! Thanks, Janusz > Keeping the per > device domain info while device is unplugged is a bit dangerous because > info->dev might be a wild pointer. We need to work out a clean fix. > > > > > Thanks, > > Janusz > > > > Best regards, > Baolu > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu