From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:50864)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <rjones@redhat.com>) id 1RHFq9-0006Rd-3U
	for qemu-devel@nongnu.org; Fri, 21 Oct 2011 10:12:54 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <rjones@redhat.com>) id 1RHFq7-0000K8-CW
	for qemu-devel@nongnu.org; Fri, 21 Oct 2011 10:12:52 -0400
Received: from mx1.redhat.com ([209.132.183.28]:39226)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <rjones@redhat.com>) id 1RHFq7-0000Jl-5Q
	for qemu-devel@nongnu.org; Fri, 21 Oct 2011 10:12:51 -0400
Date: Fri, 21 Oct 2011 15:12:41 +0100
From: "Richard W.M. Jones" <rjones@redhat.com>
Message-ID: <20111021141241.GV8872@amd.home.annexia.org>
References: <4EA1244C.4020006@cn.fujitsu.com>
	<dcfaf76d-0e02-4e19-8c64-e0d127907398@zmail05.collab.prod.int.phx2.redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <dcfaf76d-0e02-4e19-8c64-e0d127907398@zmail05.collab.prod.int.phx2.redhat.com>
Subject: Re: [Qemu-devel] [Question] dump memory when host pci device is
 used by guest
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Dave Anderson <anderson@redhat.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>, Luiz Capitulino <lcapitulino@redhat.com>, KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>, qemu-devel <qemu-devel@nongnu.org>

On Fri, Oct 21, 2011 at 09:02:37AM -0400, Dave Anderson wrote:
> It would be kind of cool if there was a "/dev/mem"-like interface
> to a KVM guest's physical memory, so that you could sit on a KVM host
> and enter "crash vmlinux-of-guest /dev/mem-of-guest" in order to
> run live analysis of a guest.

OT for this thread, but this sort of thing does exist, kind of.

You can send monitor commands to qemu to read physical and virtual
memory ("pmemsave" and "memsave" respectively).  At least one, and
possibly now both of these are bound through libvirt APIs:

http://libvirt.org/html/libvirt-libvirt.html#virDomainMemoryPeek

Here was your previous response about 4 years ago:

https://www.redhat.com/archives/crash-utility/2008-August/msg00032.html

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://libguestfs.org