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RE: [Xen-devel] [PATCH] [VTD] Enable pass-through translation for Dom0

To: <Xen-devel@xxxxxxxxxxxxxxxxxxx>, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx>
Subject: RE: [Xen-devel] [PATCH] [VTD] Enable pass-through translation for Dom0
From: "Han, Weidong" <weidong.han@xxxxxxxxx>
Date: Tue, 9 Sep 2008 16:34:01 +0800
Cc: "Cihula, Joseph" <joseph.cihula@xxxxxxxxx>, "Xu, Anthony" <anthony.xu@xxxxxxxxx>, "Kay, Allen M" <allen.m.kay@xxxxxxxxx>
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Thread-topic: [Xen-devel] [PATCH] [VTD] Enable pass-through translation for Dom0
Taking security into accout, it's not suitable to enable pass-through
translation for Dom0 by default when the pass-through field in extended
capability register is set. This feature is for people/usages who are
not overly worried about security/isolation, but want best performance.
With Dom0 use of pass-through, it reduces the IOTLB pressure for other
devices assigned to guest domains. 


Is it possible to add a command line option to control whether this is

Randy (Weidong)

Han, Weidong wrote:
> If pass-through field in extended capability register is set, set
> pass-through translation type for Dom0, that means DMA requests with
> Untranslated addresses are
> processed as pass-through in Dom0, needn't translate DMA requests
> through a multi-level page-table.
> Signed-off-by: Anthony Xu <anthony.xu@xxxxxxxxx>
> Signed-off-by: Weidong Han <weidong.han@xxxxxxxxx>

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