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Re: [Xen-devel] Re: [PATCH]Add a flag for shadow pages

To: "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx>, Tim Deegan <Tim.Deegan@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Re: [PATCH]Add a flag for shadow pages
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Wed, 04 Mar 2009 14:30:10 +0000
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Thread-topic: [Xen-devel] Re: [PATCH]Add a flag for shadow pages
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On 04/03/2009 11:57, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:

> On 04/03/2009 09:56, "Keir Fraser" <keir.fraser@xxxxxxxxxxxxx> wrote:
>> Another would be to create a new function page_get_reference_and_owner()
>> which obtains a reference on a guest page and *returns* the (now known
>> valid) domain pointer. Probably this is nicer actually. Then all existing
>> users of page_get_owner() need checking to ensure they don't need to use the
>> new more expensive function -- I think some are probably actually unsafe now
>> that shadow pages clobber the domain field.
> I'm working on this by the way. I'll clean up everything except shadow uses
> of page_get_owner().

Changeset 19268. See get_page_from_l1e() for an example safe usage of new
page_get_owner_and_reference() function.

 -- Keir

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