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/
Home Products Support Community News


[Xen-devel] question on iommu _map_page

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] question on iommu _map_page
From: Kaushik Kumar Ram <kaushik@xxxxxxxx>
Date: Thu, 27 May 2010 15:37:10 -0500
Delivery-date: Thu, 27 May 2010 13:38:10 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
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
Hi all,

I am trying to use the VT-d support with a PV driver domain which performs 
network I/O on behalf of guest domains. 
When I initiate any network I/O it results in I/O page faults. On taking a 
closer look I find that iommu_map_page() is called only for writable pages from 
__gnttab_map_grant_ref(). This results in page faults during packet 
transmission since pages are mapped read-only in this case. 
When I remove this restriction, I can get it working without any page faults. 

Is this a bug? or am I missing something here? I am using the latest unstable 
version of Xen. This part of the source code hasn't changed in a long time.

Xen-devel mailing list

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