WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

RE: [Xen-devel] HVM guest sees two NICs even though just one vif configu

To: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Subject: RE: [Xen-devel] HVM guest sees two NICs even though just one vif configured
From: "Fischer, Anna" <anna.fischer@xxxxxx>
Date: Thu, 6 Aug 2009 10:24:22 +0000
Accept-language: en-US
Acceptlanguage: en-US
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Thu, 06 Aug 2009 03:25:26 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <C6A06C22.1173D%keir.fraser@xxxxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <0199E0D51A61344794750DC57738F58E6D6A501125@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> <C6A06C22.1173D%keir.fraser@xxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcoWeM3QdTRjgnaEQhqqXuFH+NHM2wABjUoZAAAPXjA=
Thread-topic: [Xen-devel] HVM guest sees two NICs even though just one vif configured
> Subject: Re: [Xen-devel] HVM guest sees two NICs even though just one
> vif configured
> 
> On 06/08/2009 10:32, "Fischer, Anna" <anna.fischer@xxxxxx> wrote:
> 
> > For me this does not sound right. If I configure my guest with only a
> single
> > NIC in the configuration file, then there should not be any way for
> the guest
> > to set up and use two NICs at the same time.
> >
> > Is this a known issue? How is this supposed to be handled?
> 
> I think it's deliberate, to allow install of an OS with emulated
> driver,
> followed by switchover to PV drivers, wth no need for config changes.

I assumed that was the reason behind this. However, a switchover would need to 
guarantee that a guest cannot use two NICs at the same time, doesn't it? 
Because otherwise the guest can send out of two separate devices at the same 
time and it could cause unexpected behaviour unless it is explicitly prevented 
at the backends in Dom0, e.g. through filtering or anti-spoofing I guess.

Anna

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel