From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Dutile Subject: Re: [PATCH v2] Enhance dmar to support device hotplug Date: Tue, 10 Dec 2013 12:03:25 -0500 Message-ID: <52A7495D.6010905@redhat.com> References: <1385022116-228-1-git-send-email-wangyijing@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1385022116-228-1-git-send-email-wangyijing-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Yijing Wang Cc: Vinod Koul , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, dmaengine-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Hanjun Guo , Bjorn Helgaas , Dan Williams , David Woodhouse List-Id: iommu@lists.linux-foundation.org On 11/21/2013 03:21 AM, Yijing Wang wrote: > This is the v2 patch, the v1 link: http://marc.info/?l=linux-pci&m=138364004628824&w=2 > > v1->v2: keep (pci_dev *) pointer array in dmar_drhd_uni, only use pci device id > to update pci_dev * pointer info during device hotplug in intel iommu > driver notifier. > > Currently, DMAR driver save target pci devices pointers for drhd/rmrr/atsr > in (pci_dev *) array, but never update these info after initialization. > It's not safe, because pci devices maybe hot added or removed during > system running. They will have new pci_dev * pointer. So if there have > two IOMMUs or more in system, these devices will find a wrong drhd during > DMA mapping. And DMAR faults will occur. This patch save pci device id > as well as (pci_dev *) to fix this issue. Pci device id will be used to update > pci_dev * poninter during device hotplug in intel iommu driver notifier. > Other, here use list to manage target devices for IOMMU, > we can easily use list helper. > > Yijing Wang (1): > IOMMU: enhance dmar to support device hotplug > > drivers/iommu/dmar.c | 82 +++++++++++----------- > drivers/iommu/intel-iommu.c | 161 +++++++++++++++++++++++++++++------------- > include/linux/dmar.h | 24 ++++-- > 3 files changed, 167 insertions(+), 100 deletions(-) > > > _______________________________________________ > iommu mailing list > iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu > Can this bug & fix be demonstrated by configuring & de-configuring VFs on an SRIOV device, since that effectively looks like a hot-add & hot-remove ? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754918Ab3LJREH (ORCPT ); Tue, 10 Dec 2013 12:04:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41270 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754413Ab3LJRD7 (ORCPT ); Tue, 10 Dec 2013 12:03:59 -0500 Message-ID: <52A7495D.6010905@redhat.com> Date: Tue, 10 Dec 2013 12:03:25 -0500 From: Don Dutile User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20131028 Thunderbird/17.0.10 MIME-Version: 1.0 To: Yijing Wang CC: Alex Williamson , Bjorn Helgaas , Joerg Roedel , David Woodhouse , Vinod Koul , linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, Hanjun Guo , dmaengine@vger.kernel.org, Dan Williams Subject: Re: [PATCH v2] Enhance dmar to support device hotplug References: <1385022116-228-1-git-send-email-wangyijing@huawei.com> In-Reply-To: <1385022116-228-1-git-send-email-wangyijing@huawei.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/21/2013 03:21 AM, Yijing Wang wrote: > This is the v2 patch, the v1 link: http://marc.info/?l=linux-pci&m=138364004628824&w=2 > > v1->v2: keep (pci_dev *) pointer array in dmar_drhd_uni, only use pci device id > to update pci_dev * pointer info during device hotplug in intel iommu > driver notifier. > > Currently, DMAR driver save target pci devices pointers for drhd/rmrr/atsr > in (pci_dev *) array, but never update these info after initialization. > It's not safe, because pci devices maybe hot added or removed during > system running. They will have new pci_dev * pointer. So if there have > two IOMMUs or more in system, these devices will find a wrong drhd during > DMA mapping. And DMAR faults will occur. This patch save pci device id > as well as (pci_dev *) to fix this issue. Pci device id will be used to update > pci_dev * poninter during device hotplug in intel iommu driver notifier. > Other, here use list to manage target devices for IOMMU, > we can easily use list helper. > > Yijing Wang (1): > IOMMU: enhance dmar to support device hotplug > > drivers/iommu/dmar.c | 82 +++++++++++----------- > drivers/iommu/intel-iommu.c | 161 +++++++++++++++++++++++++++++------------- > include/linux/dmar.h | 24 ++++-- > 3 files changed, 167 insertions(+), 100 deletions(-) > > > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu > Can this bug & fix be demonstrated by configuring & de-configuring VFs on an SRIOV device, since that effectively looks like a hot-add & hot-remove ?