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[Xen-devel] detecting paging inside of VMs

To: "Xen Devel" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: [Xen-devel] detecting paging inside of VMs
From: "Tim Wood" <twwood@xxxxxxxxx>
Date: Wed, 21 Jun 2006 11:10:26 -0400
Delivery-date: Wed, 21 Jun 2006 08:10:49 -0700
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I'd like to be able to detect when a VM is pressed for memory without doing anything inside of the VM. 

My idea is to add some code in the hypervisor that would try to detect paging in each domU, or maybe just monitor the rate at which memory pages are being requested and released.

I know that the guest OSes are responsible for managing their own page tables, but I suspect that some of this still goes through the VMM.

I'm willing to do some hacking, but I'm not yet sure if the information I'd need can be obtained in the hypervisor.  I'd rather not modify the user level xen kernels if possible.

Does any of this seem plausible?  Thanks for any info!

-Tim

p.s. of course if you have any other ideas (that are transparent to the domU) I'd be interested to hear
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