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] Xen, IRQ-sharing and PCI passthrough

To: Florian Wagner <f_wagner@xxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Subject: Re: [Xen-devel] Xen, IRQ-sharing and PCI passthrough
From: Keir Fraser <keir.fraser@xxxxxxxxxxxxx>
Date: Wed, 08 Jul 2009 08:31:29 +0100
Cc:
Delivery-date: Wed, 08 Jul 2009 00:32:08 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20090708083513.774b8281@xxxxxxxxxxxxxxxxx>
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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: Acn/lldocUy2hDwDQxGlWmCw5tbv0wAB8Q38
Thread-topic: [Xen-devel] Xen, IRQ-sharing and PCI passthrough
User-agent: Microsoft-Entourage/12.19.0.090515
On 08/07/2009 07:35, "Florian Wagner" <f_wagner@xxxxxxxxxx> wrote:

> Do I understand this correctly: For safe operation of a virtual machine
> using PCI passthrough and shared interrupts a well behaved operating
> system in the vm is necessary. That is an OS that shuts down the mapped
> devices correctly before turning off (unload kernel module).
> 
> So what am I to to in the case that someone issues a "xm destroy" on
> such a vm? There is no way to cleanly shutdown in such a situation, is
> there?
> 
> That's quite a risk for system stability of the host. One thoughtless
> "xm destroy" and the whole host is crashed, requiring at a minimum a
> cold reset or even a reinstall.

We're probably missing a device reset somewhere during domain destruction.
Or it may be happening too late. Still there is a limit to VM isolation when
IRQs are shared. The best bet is to use MSI, if one of your devices supports
it. That would require Xen 3.4.

 -- Keir



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

<Prev in Thread] Current Thread [Next in Thread>