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Re: [Xen-devel] Xen memory management

To: Jonathan Tripathy <jonnyt@xxxxxxxxxxx>
Subject: Re: [Xen-devel] Xen memory management
From: David Xu <davidxu06@xxxxxxxxx>
Date: Thu, 23 Jun 2011 19:50:36 -0400
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Sounds good. Does Xen VMM can control the mapping between a part of memory and cache line? That is to say I wander whether Xen can guarantee different VMs will use different cache line. Thanks.

Regards,
Cong

2011/6/23 Jonathan Tripathy <jonnyt@xxxxxxxxxxx>

On 23/06/2011 23:08, David Xu wrote:
Thanks. My concern is that if several VMs are mapped to same memory, one VM may get something from the memory which has ever been used by another VM. This may cause some secure problems. 



Someone correct me if I'm wrong, but I'm pretty sure that a DomU kernel (If the flag is set correctly during compile time) will scrub (i.e. "zero") RAM first before releasing it to the Xen Hypervisor. Then hypervisor will then subsequently assign that bit of RAM to another domain.

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