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From: Andy Smith <andy@strugglers.net>
To: xen-devel@lists.xen.org
Subject: Re: Possible to prevent dom0 accessing guest memory?
Date: Mon, 14 Nov 2016 15:29:32 +0000	[thread overview]
Message-ID: <20161114152932.GL1804@bitfolk.com> (raw)
In-Reply-To: <ff23faef-fdb1-0cb3-e0db-cfec532768d4@citrix.com>

Hi Andrew,

On Mon, Nov 14, 2016 at 03:06:12PM +0000, Andrew Cooper wrote:
> You have misunderstood a step.
> 
> Dom0 can map all of guest memory.  This is how `xl dump-core` is
> implemented, as well as how Qemu emulates devices for the guest.

Ah, okay, thanks. That is what I feared.

Due to details of the legal jurisdiction in which I operate, it
would actually be useful to me to disable xl dump-core and be able
to truthfully state that I do not know how to obtain a dump of a
guest's memory. As it stands I do know that xl dump-core exists and
I can be compelled to run it. I do not personally know how to write
a program to do what xl dump-core does and would have no interest in
finding out.

But I appreciate that the more general concern would be an attacker
who gains root access, and they could just run such a program, so I
guess Xen developers would see little point in offering a way to
disable dump-core.

Cheers,
Andy

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  reply	other threads:[~2016-11-14 15:29 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-11-14 14:51 Possible to prevent dom0 accessing guest memory? Andy Smith
2016-11-14 15:06 ` Andrew Cooper
2016-11-14 15:29   ` Andy Smith [this message]
2016-11-14 17:09     ` George Dunlap
2016-11-14 20:35       ` Andy Smith

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