From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga05.intel.com ([192.55.52.43]:20602 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726181AbgFAXUQ (ORCPT ); Mon, 1 Jun 2020 19:20:16 -0400 Subject: Re: [PATCH v2 00/33] iommu: Move iommu_group setup to IOMMU core code References: <20200414131542.25608-1-joro@8bytes.org> <20200529221623.qc6twmpzryh7nkvb@cantor> <20200601104240.7f5xhz7gooqhaq4n@cantor> From: Lu Baolu Message-ID: <47711845-98ee-95b8-aa95-423a36ed9741@linux.intel.com> Date: Tue, 2 Jun 2020 07:16:22 +0800 MIME-Version: 1.0 In-Reply-To: <20200601104240.7f5xhz7gooqhaq4n@cantor> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: Joerg Roedel , Will Deacon , Robin Murphy , Marek Szyprowski , Kukjin Kim , Krzysztof Kozlowski , David Woodhouse , Andy Gross , Bjorn Andersson , Matthias Brugger , Rob Clark , Heiko Stuebner , Gerald Schaefer , Thierry Reding , Jonathan Hunter , Jean-Philippe Brucker , linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-rockchip@lists.infradead.org, iommu@lists.linux-foundation.org, linux-mediatek@lists.infradead.org, linux-tegra@vger.kernel.org Cc: baolu.lu@linux.intel.com Hi Jerry, On 6/1/20 6:42 PM, Jerry Snitselaar wrote: >> >> Hi Joerg, >> >> With this patchset, I have an epyc system where if I boot with >> iommu=nopt and force a dump I will see some io page faults for a nic >> on the system. The vmcore is harvested and the system reboots. I >> haven't reproduced it on other systems yet, but without the patchset I >> don't see the io page faults during the kdump. >> >> Regards, >> Jerry > > I just hit an issue on a separate intel based system (kdump iommu=nopt), > where it panics in during intel_iommu_attach_device, in is_aux_domain, > due to device_domain_info being DEFER_DEVICE_DOMAIN_INFO. That doesn't > get set to a valid address until the domain_add_dev_info call. > > Is it as simple as the following? I guess you won't hit this issue if you use iommu/next branch of Joerg's tree. We've changed to use a generic helper to retrieve the valid per device iommu data or NULL (if there's no). Best regards, baolu > > diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c > index 29d3940847d3..f1bbeed46a4c 100644 > --- a/drivers/iommu/intel-iommu.c > +++ b/drivers/iommu/intel-iommu.c > @@ -5053,8 +5053,8 @@ is_aux_domain(struct device *dev, struct > iommu_domain *domain) >  { >         struct device_domain_info *info = dev->archdata.iommu; > > -       return info && info->auxd_enabled && > -                       domain->type == IOMMU_DOMAIN_UNMANAGED; > +       return info && info != DEFER_DEVICE_DOMAIN_INFO && > +               info->auxd_enabled && domain->type == > IOMMU_DOMAIN_UNMANAGED; >  } > >  static void auxiliary_link_device(struct dmar_domain *domain, > > > Regards, > Jerry