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Re: [Xen-devel] RE: information leaking between domains via granted page

To: James Harper <james.harper@xxxxxxxxxxxxxxxx>, "Santos, Jose Renato G" <joserenato.santos@xxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] RE: information leaking between domains via granted pages?
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Tue, 04 Mar 2008 08:49:06 +0000
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On 4/3/08 08:21, "James Harper" <james.harper@xxxxxxxxxxxxxxxx> wrote:

>>   This is not a problem today as DomU is not granted access to any
> Dom0
>> page. DomU is the one which grants access to dom0 both for TX and RX.
>>   On the other hand dom0 can access any data in granted domU pages but
>> this is OK as we trust dom0.
> 
> Maybe I'm mistaken about the way 'page flipping' on the rx path works
> then... care to enlighten me?

The flipping path is not high performance these days as we expect only very
old domUs to use it. All skbuffs destined for a flipping interface are
laundered through netbk_copy_skb(). Note its judicious use of __GFP_ZERO.

 -- Keir



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