linux-kernel - Re: [PATCH] iommu/vt-d: Handle hotplug devices' default identity mapping setting

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <21c17b44-af9b-2f18-f109-ba4bb0635e61@linux.intel.com>
Date:   Fri, 22 Feb 2019 15:42:02 +0800
From:   Lu Baolu <baolu.lu@...ux.intel.com>
To:     James Dong <xmdong@...gle.com>
Cc:     baolu.lu@...ux.intel.com, David Woodhouse <dwmw2@...radead.org>,
        Joerg Roedel <joro@...tes.org>,
        iommu@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
        Jis Ben <jisben@...gle.com>
Subject: Re: [PATCH] iommu/vt-d: Handle hotplug devices' default identity
 mapping setting

Hi James,

On 2/22/19 2:38 PM, James Dong wrote:
> 
> Tried this patch, and the same DMAR fault message came out.
> 
> Guess it is because of the iommu code path for hotplug devices. If a hotplug
> device is rescanned after removal, iommu_bus_notifier will be called as part
> of the notifier chains to handle BUS_NOTIFY_ADD_DEVICE event. Along the code
> path, intel_iommu_ops->add_device() created an iommu group for this hotplug
> device, but failed to create an iommu domain because of the default domain
> type IOMMU_DOMAIN_IDENTITY imposed by current IOMMU command line option got
> declined by intel_iommu_ops->domain_alloc().
> 
> In your patch, function find_or_alloc_domain() is not even in the code path
> of BUS_NOTIFY_ADD_DEVICE event notifier chain.
> 
> Please let us know if your have more concerns and suggestions.

Can I reproduce this with a local machine? If so, how should I do?

> 
> Best Regards,
> James

Best regards,
Lu Baolu