From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: pciback: question about the permissive flag
Date: Wed, 7 Jul 2010 07:32:12 +0100
Message-ID: <C859DDFC.1996A%keir.fraser@eu.citrix.com>
References: <4C33A217.3050006@invisiblethingslab.com>
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To: Joanna Rutkowska <joanna@invisiblethingslab.com>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>
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On 06/07/2010 22:37, "Joanna Rutkowska" <joanna@invisiblethingslab.com>
wrote:

> So, what am I missing here?

I think the fear was that there could be class- or device-specific config
registers that we wouldn't know how to handle, and which could have
unexpected effects if they are passed through naively. Concrete examples
were never given, and this was all pre-vtd so as you say pass-through of a
DMA-capable device was insecure anyway. I've always thought the permissive
flag stuff was pretty useless, and I always suggest people to enable the
permissive flag.

 -- Keir