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[Xen-devel] Re: one question to p2m table entry type

To: Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>
Subject: [Xen-devel] Re: one question to p2m table entry type
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 18 May 2010 13:28:55 +0100
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On 18/05/2010 12:04, "Tim Deegan" <Tim.Deegan@xxxxxxxxxxxxx> wrote:

>> But since we don't support pure 32 bit xen hypervisor any more, and
>> for 32 PAE, we are sure have enough bit to keep these flags, why do we
>> need these special handling? Are there any special reason for it?
> The Intel SDMs (section 3.8.5, figure 3-20 in the copy in front of me)
> only define three available bits in PAE PTEs; all bits above MAXPHYADDR
> are reserved.  If we can rely on the manuals being wrong about that, we
> can extend the number of p2m types on 32-bit XEN. :)

If I previously replied positively about this patch, it's because I forgot
about the above PAE restriction.

 -- Keir

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