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Re: [Xen-devel] changing shadow page

To: Johnny R <xen4wr@xxxxxxxxx>
Subject: Re: [Xen-devel] changing shadow page
From: George Dunlap <dunlapg@xxxxxxxxx>
Date: Thu, 30 Jun 2011 10:45:05 +0100
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On Wed, Jun 29, 2011 at 4:35 PM, Johnny R <xen4wr@xxxxxxxxx> wrote:
> As a newbie in Xen,i have been assigned a task recently.It about changing
> all the page into write-protected in order to catch all the info written
> into the page.
> However,i hope that somebody can shed some light on how the shadow page work
> in Xen.Thanks a lot

Please read http://wiki.xensource.com/xenwiki/AskingXenDevelQuestions.

I sympathize with you being assigned a task in a very complicated
piece of code with which you have no experience.  Unfortunately, your
question as asked would require a small book to answer; and while all
of us are happy to help people learn, none of us are trained in
education nor paid to do so.

Your best bet might be to start looking at the page-sharing code or
the hypervisor paging code, both of which involve removing write
protection from guest pages.  Find all the places this code touches,
and try to understand how it works; and if you get stuck, ask a
specific question about the code. You're more likely to get a useful

(That's assuming that you already have a familiarity with how
pagetables work in general; if not, please make sure you review and
thoroughly understand that first.)

Good luck,

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