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Re: [Xen-devel] high memory dma update: up against a wall

To: Jon Mason <jdmason@xxxxxxxxxx>
Subject: Re: [Xen-devel] high memory dma update: up against a wall
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Wed, 13 Jul 2005 09:48:47 +0100
Cc: xen-devel@xxxxxxxxxxxxxxxxxxx, Scott Parish <srparish@xxxxxxxxxx>
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On 13 Jul 2005, at 00:21, Jon Mason wrote:

AMD64 has IOMMU HW acceleration. EM64T has software IOMMU. Whenever I get
IOMMU working on x86-64, this should solve your problem.

If dom0 controls the IOMMU (instead of Xen) then that will be a good solution for dom0 drivers. For other domains, with no control over a IOMMU, we'll probably fall back to bounce buffers with an associated drop in performance.

Most people run drivers in dom0 anyway.

 -- Keir

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