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Date:   Fri, 30 Aug 2019 12:31:51 +0200
From:   Joerg Roedel <joro@8bytes.org>
To:     Lu Baolu <baolu.lu@linux.intel.com>
Cc:     David Woodhouse <dwmw2@infradead.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Christoph Hellwig <hch@lst.de>, ashok.raj@intel.com,
        jacob.jun.pan@intel.com, alan.cox@intel.com, kevin.tian@intel.com,
        mika.westerberg@linux.intel.com, Ingo Molnar <mingo@redhat.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        pengfei.xu@intel.com,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Marek Szyprowski <m.szyprowski@samsung.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Boris Ostrovsky <boris.ostrovsky@oracle.com>,
        Juergen Gross <jgross@suse.com>,
        Stefano Stabellini <sstabellini@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
        Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: Re: [PATCH v7 1/7] iommu/vt-d: Don't switch off swiotlb if use
 direct dma
Message-ID: <20190830103150.GB29382@8bytes.org>
References: <20190823071735.30264-1-baolu.lu@linux.intel.com>
 <20190823071735.30264-2-baolu.lu@linux.intel.com>
 <20190823083956.GB24194@8bytes.org>
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On Sat, Aug 24, 2019 at 10:17:30AM +0800, Lu Baolu wrote:
> If a system has any external port, through which an untrusted device
> might be connected, the external port itself should be marked as an
> untrusted device, and all devices beneath it just inherit this
> attribution.

Okay, makes sense.

> So during iommu driver initialization, we can easily know whether the
> system has (or potentially has) untrusted devices by iterating the
> device tree. I will add such check in the next version if no objections.

Sounds good, thanks Baolu.


	Joerg