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[Xen-devel] Re: [PATCH] Allow removing writable mappings from splintered

To: "Gianluca Guida" <gianluca.guida@xxxxxxxxxxxxx>
Subject: [Xen-devel] Re: [PATCH] Allow removing writable mappings from splintered page tables.
From: "Todd Deshane" <deshantm@xxxxxxxxx>
Date: Fri, 12 Sep 2008 13:08:34 -0400
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On Fri, Sep 12, 2008 at 12:51 PM, Gianluca Guida
<gianluca.guida@xxxxxxxxxxxxx> wrote:
> Hello,
> The moving of the pagetable mapping in the linux kernel exposed the fact
> that under the linux kernel sh_rm_write_access_from_sl1p was always failing.
> Linux seems to use big pages to access page tables, so we should instruct
> the shadow code to be able to remove writable mappings from splintered
> pagetables as well, avoiding using OS heuristic (which were failing in
> 2.6.27 before George patch, leading to brute-force search at each resync).
> Todd: Can you try try the linux-2.6.27 kernbench with the following patch?
> Also, are you using ioemu stub-domains? That should also give a performance
> gain.

Sure, I can give it a try. Should I also apply George's patch right?

I am not using ioemu stub-domains yet, would you recommend them in a general
sense or are they more of a special case?


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