From mboxrd@z Thu Jan  1 00:00:00 1970
From: Anthony Liguori <aliguori@linux.vnet.ibm.com>
Subject: Re: [PATCH  -v2] Monitor command: pfa2hva, translate guest	physical
 address to host virtual address
Date: Wed, 10 Nov 2010 10:49:55 -0600
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Cc: Huang Ying <ying.huang@intel.com>,
	Marcelo Tosatti <mtosatti@redhat.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Andi Kleen <andi@firstfloor.org>,
	Dean Nelson <dnelson@redhat.com>,
	Luiz Capitulino <lcapitulino@redhat.com>
To: Avi Kivity <avi@redhat.com>
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On 11/10/2010 02:34 AM, Avi Kivity wrote:
>> Why the gpa ->  hva mapping is not
>> consistent for RAM if -mempath is not used?
>
> Video RAM in the range a0000-bffff and PCI mapped RAM can change gpas 
> (while remaining in the same hva).
>
> Even for ordinary RAM, which doesn't normally change gpa/hva, I'm not 
> sure we want to guarantee that it won't.

We can't universally either.  Memory hot remove potentially breaks the 
mapping and some non-x86 architectures (like ARM) can alias RAM via a 
guest triggered mechanism.

Regards,

Anthony Liguori