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[Xen-devel][PATCH][VT-d] Dis-allow PCI device assignment if PoD is enabl

To: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel][PATCH][VT-d] Dis-allow PCI device assignment if PoD is enabled
From: "Xu, Dongxiao" <dongxiao.xu@xxxxxxxxx>
Date: Thu, 21 Jan 2010 20:28:13 +0800
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Cc: "George.Dunlap@xxxxxxxxxxxxx" <George.Dunlap@xxxxxxxxxxxxx>, "Han, Weidong" <weidong.han@xxxxxxxxx>, Keir Fraser <keir.fraser@xxxxxxxxxxxxx>, "Cui, Dexuan" <dexuan.cui@xxxxxxxxx>
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Thread-topic: [Xen-devel][PATCH][VT-d] Dis-allow PCI device assignment if PoD is enabled
It seems that currently we don't have any code to handle
the coexistence of VT-d and PoD. VT-d engine needs to set up
the entire page table for the domain. However if PoD is enabled,
un-populated memory is marked as populate_on_demand, and
VT-d engine won't set up page tables for them. Therefore any
DMA towards those memory may cause DMA fault.
        So for safety concern, its better to dis-allow PCI device
assignment if PoD is enabled.

Best Regards, 
-- Dongxiao

Attachment: pod_disable_dev_assign.patch
Description: pod_disable_dev_assign.patch

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