From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([140.186.70.92]:60481)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <B07421@freescale.com>) id 1QchqQ-0003kb-7V
	for qemu-devel@nongnu.org; Fri, 01 Jul 2011 13:49:35 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <B07421@freescale.com>) id 1QchqL-0000oQ-2c
	for qemu-devel@nongnu.org; Fri, 01 Jul 2011 13:49:33 -0400
Received: from tx2ehsobe004.messaging.microsoft.com ([65.55.88.14]:6035
	helo=TX2EHSOBE007.bigfish.com) by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <B07421@freescale.com>) id 1QchqK-0000nz-L1
	for qemu-devel@nongnu.org; Fri, 01 Jul 2011 13:49:28 -0400
Date: Fri, 1 Jul 2011 12:49:15 -0500
From: Scott Wood <scottwood@freescale.com>
Message-ID: <20110701124915.5343a033@schlenkerla.am.freescale.net>
In-Reply-To: <201107011803.01887.paul@codesourcery.com>
References: <9F6FE96B71CF29479FF1CDC8046E1503165EEB@039-SN1MPN1-003.039d.mgd.msft.net>
	<4E0DB945.4070203@codemonkey.ws>
	<20110701114301.08d0154b@schlenkerla.am.freescale.net>
	<201107011803.01887.paul@codesourcery.com>
MIME-Version: 1.0
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] device assignment for embedded Power
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: Paul Brook <paul@codesourcery.com>
Cc: Wood Scott-B07421 <B07421@freescale.com>, Alexander Graf <agraf@suse.de>, "qemu-devel@nongnu.org" <qemu-devel@nongnu.org>, "blauwirbel@gmail.com" <blauwirbel@gmail.com>, Yoder Stuart-B08248 <B08248@freescale.com>, "alex.williamson@redhat.com" <alex.williamson@redhat.com>, "joerg.roedel@amd.com" <joerg.roedel@amd.com>, "dwg@au1.ibm.com" <dwg@au1.ibm.com>, "armbru@redhat.com" <armbru@redhat.com>

On Fri, 1 Jul 2011 18:03:01 +0100
Paul Brook <paul@codesourcery.com> wrote:

> Basically you should start by implementing full emulation of a device with 
> similar characteristics to the one you want to passthrough.

That's not going to happen.

> Once you've done all the above, host device passthrough should be relatively 
> straightforward.  Just replace the emulation bits in the above device with 
> code that pokes at a real device via the relevant kernel API.

That's not what we mean by direct device assignment.

We're talking about directly mapping the registers into the guest.  The
whole point is performance.

-Scott