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Re: [Xen-devel] Implementing split memory in Xen is annoyingly hard?

To: Sina Bahram <sbahram@xxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>, <xen-research@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Implementing split memory in Xen is annoyingly hard?
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Fri, 12 Dec 2008 09:19:58 +0000
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On 12/12/2008 06:47, "Sina Bahram" <sbahram@xxxxxxxxx> wrote:

> #2: Xen absolutely does not, (can not?), cause a fault or other VM exit to
> be generated upon an execute or a read of a page.

It's not possible to make a page executable but not readable, so indeed I
think you're stumped there, unless you can work out a hackish way to
desynchronise the iTLB and the dTLB (an operation not supported
architecturally by x86 of course).

 -- Keir

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