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RE: [Xen-devel] Questions about writing to GCMD_REG in iommu.c

To: "Neo Jia" <neojia@xxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: RE: [Xen-devel] Questions about writing to GCMD_REG in iommu.c
From: "Han, Weidong" <weidong.han@xxxxxxxxx>
Date: Mon, 14 Jul 2008 17:10:56 +0800
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Thread-topic: [Xen-devel] Questions about writing to GCMD_REG in iommu.c
Current code has guaranteed this. After writing GCMD_REG, there is a
checking to make sure hardware completing it. Can you point out the code
which misses the check?

Randy (Weidong)

Neo Jia wrote:
> hi,
> 
> I am reading through the code of writing GCMD_REG in iommu.c for VT-d
> on xen-unstable tip. According to the Intel VT-d spec. it looks that
> we have to make sure that only one bit of this register is modified at
> one time with one register write. But the current code doesn't do that
> kind of checking, right?
> 
> Thanks,
> Neo


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