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Re: [Xen-devel] update_va_mapping_otherdomain

To: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] update_va_mapping_otherdomain
From: "Michael R. Hines" <mhines@xxxxxxxxxxxxxxxxx>
Date: Sun, 09 Sep 2007 14:24:36 -0400
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Thank you.

- Michael

Keir Fraser wrote:
> There is currently no way to modify active page tables of another domain.
> 
>  -- Keir
> 
> 
> On 8/9/07 19:27, "Michael R. Hines" <mhines@xxxxxxxxxxxxxxxxx> wrote:
> 
>> So, if I would like to use dom0 to modify a specific L1 PTE belonging
>> to another unprivileged domain, what's the best way to go about it?
>>
>> Grant references? (on L1 page tables?)
>>
>> Might I be able to get a quick pointer on the right sequence of hypercalls?
>>
>> Much appreciated,
>> - Michael
>>
>> Michael R. Hines wrote:
>>> ooooh, ok. I understand now.
>>>
>>> Thank you very much for your response. =)
>>>
>>> - Michael
>>>
>>> Keir Fraser wrote:
>>>> On 8/9/07 02:29, "Michael R. Hines" <mhines@xxxxxxxxxxxxxxxxx> wrote:
>>>>
>>>>> Upon successful return from update_va_mapping (i.e. return code == zero),
>>>>> my problem involves the last step mentioned above. The present bit still
>>>>> remains unchanged (is still one), although update_va_mapping return true.
>>>>>
>>>>> What might cause such a strange problem to occur?
>>>> That hypercall allows you to update a *local* va mapping to map *another*
>>>> domain's memory page. So you've mapped the guest's page somewhere random in
>>>> your own address space.
>>>>
>>>>  -- Keir
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
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>>>> Xen-devel@xxxxxxxxxxxxxxxxxxx
>>>> http://lists.xensource.com/xen-devel
>>>>
>>>
>>> ------------------------------------------------------------------------
>>>
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> 
> 
> 

-- 
/*
Michael R. Hines
http://www.cs.binghamton.edu/~mhines/
Live long and prosper...
*/

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