linux-kernel - Re: [PATCH v2 09/16] driver core: add iommu device fault reporting data

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

Message-ID: <20171006082603.GA3836@kroah.com>
Date:   Fri, 6 Oct 2017 10:26:03 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Christoph Hellwig <hch@...radead.org>
Cc:     Jacob Pan <jacob.jun.pan@...ux.intel.com>,
        iommu@...ts.linux-foundation.org,
        LKML <linux-kernel@...r.kernel.org>,
        Joerg Roedel <joro@...tes.org>,
        David Woodhouse <dwmw2@...radead.org>,
        Rafael Wysocki <rafael.j.wysocki@...el.com>,
        Jean-Philippe Brucker <jean-philippe.brucker@....com>,
        Lan Tianyu <tianyu.lan@...el.com>
Subject: Re: [PATCH v2 09/16] driver core: add iommu device fault reporting
 data

On Fri, Oct 06, 2017 at 12:11:45AM -0700, Christoph Hellwig wrote:
> On Thu, Oct 05, 2017 at 04:03:37PM -0700, Jacob Pan wrote:
> > DMA faults can be detected by IOMMU at device level. Adding a pointer
> > to struct device allows IOMMU subsystem to report relevant faults
> > back to the device driver for further handling.
> > For direct assigned device (or user space drivers), guest OS holds
> > responsibility to handle and respond per device IOMMU fault.
> > Therefore we need fault reporting mechanism to propagate faults beyond
> > IOMMU subsystem.
> 
> We use struct device all over the system, and I don't think we should
> bloat it for fringe case IOMMU bits.
> 
> Someone really needs to take a step back and figure out how to move
> this into a structure that's only allocated for device that actually
> can do physical DMA (and/or have an iommu attached)
> 
> This is the 3rd iommu field, in addition to 8 dma-specific fields
> that we carry around for each struct device.

Ick, 8?  Yeah, it's getting big...  How about just a single pointer for
iommu and dma-specific stuff that you all can hang crap like this off
of if needed?

thanks,

greg k-h