From owner-freebsd-xen@FreeBSD.ORG  Mon Dec  1 21:54:06 2008
Return-Path: <owner-freebsd-xen@FreeBSD.ORG>
Delivered-To: freebsd-xen@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id C8A8F1065677
	for <freebsd-xen@freebsd.org>; Mon,  1 Dec 2008 21:54:06 +0000 (UTC)
	(envelope-from dfr@rabson.org)
Received: from itchy.rabson.org (unknown [IPv6:2002:50b1:e8f2:1::143])
	by mx1.freebsd.org (Postfix) with ESMTP id 84F058FC22
	for <freebsd-xen@freebsd.org>; Mon,  1 Dec 2008 21:54:06 +0000 (UTC)
	(envelope-from dfr@rabson.org)
Received: from [IPv6:2001:470:909f:1:21b:63ff:feb8:5abc] (unknown
	[IPv6:2001:470:909f:1:21b:63ff:feb8:5abc])
	by itchy.rabson.org (Postfix) with ESMTP id 6BBF53FAB;
	Mon,  1 Dec 2008 21:54:05 +0000 (GMT)
Message-Id: <96346214-38CC-4EA9-97DA-C5C1EE358EDA@rabson.org>
From: Doug Rabson <dfr@rabson.org>
To: "Ivan Voras" <ivoras@gmail.com>
In-Reply-To: <9bbcef730812011045t4769cb76g2028c5f9c39af524@mail.gmail.com>
Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes
Content-Transfer-Encoding: 7bit
Mime-Version: 1.0 (Apple Message framework v929.2)
Date: Mon, 1 Dec 2008 21:54:05 +0000
References: <4389C4C1-0EEB-4841-8F02-DC44BBC223F4@rabson.org>
	<9bbcef730812011045t4769cb76g2028c5f9c39af524@mail.gmail.com>
X-Mailer: Apple Mail (2.929.2)
Cc: freebsd-xen@freebsd.org
Subject: Re: Xen stuff
X-BeenThere: freebsd-xen@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussion of the freebsd port to xen - implementation and usage
	<freebsd-xen.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-xen>,
	<mailto:freebsd-xen-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-xen>
List-Post: <mailto:freebsd-xen@freebsd.org>
List-Help: <mailto:freebsd-xen-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-xen>,
	<mailto:freebsd-xen-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 01 Dec 2008 21:54:06 -0000


On 1 Dec 2008, at 18:45, Ivan Voras wrote:

> 2008/12/1 Doug Rabson <dfr@rabson.org>:
>> I will be working on improving Xen support in FreeBSD for the new few
>
> Great!
>
>> months. My main goal is to add support for native Xen drivers to an  
>> amd64
>> kernel which is running in Xen's HVM mode. These drivers will take  
>> over from
>> the slow emulated devices and provide most of the performance  
>> benefits of a
>> paravirtualised kernel. I'm initially going to be supporting  
>> FreeBSD 6.x but
>> I will port it all forward to head and 7.x when it works properly.
>
> For the not-quite-yet-initiated : does this mean you're working on
> paravirtualized drivers for Xen dom-U ("guest" case)?

Sort of. The latest versions of Xen support something called HVM mode  
which allows it to boot a completely unmodified guest OS using  
emulated devices in a similar way to e.g. VMware Fusion. It is then  
possible to incrementally add Xen-aware paravirtualised drivers which  
can replace the emulated ones and which perform better. This is how  
they support Windows under Xen.