From mboxrd@z Thu Jan  1 00:00:00 1970
From: Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH] VT-d: Fix iommu map page for mmio pages
Date: Sat, 27 Sep 2008 13:24:31 +0300
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Cc: Anthony Liguori <anthony@codemonkey.ws>, kvm@vger.kernel.org,
	Amit Shah <amit.shah@redhat.com>,
	"Kay, Allen M" <allen.m.kay@Intel.Com>,
	Ben-Ami Yassour1 <BENAMI@il.ibm.com>
To: Muli Ben-Yehuda <muli@il.ibm.com>
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Muli Ben-Yehuda wrote:

  

>> MMIO isn't just a register window.  It may be an on-device buffer.
>>     
>
> Unlikely, but ok.
>
>   

It's unlikely in the same ways graphics cards are unlikely :)

With a multi-card setup, perhaps it is even reasonable for one card to 
dma to another.

> I strongly disagree. You are advocating something that is potentially
> unsafe---for the sake of code simplicity?! I am advocating caution in
> what we let an *untrusted* guest do.
>   

Why would it be unsafe?

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.