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] RFC -- virtualisable NIC support in Xen

To: Caitlin Bestler <caitlinb@xxxxxxxxxxxx>
Subject: Re: [Xen-devel] RFC -- virtualisable NIC support in Xen
From: Greg Law <glaw@xxxxxxxxxxxxxx>
Date: Fri, 22 Sep 2006 12:04:38 +0100
Cc: xen@xxxxxxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 22 Sep 2006 04:05:08 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <54AD0F12E08D1541B826BE97C98F99F1A30F2F@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
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/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <54AD0F12E08D1541B826BE97C98F99F1A30F2F@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Mozilla Thunderbird 1.0.7-1.1.fc3 (X11/20050929)
Caitlin Bestler wrote:
When the App/DomU posts a buffer (for TX or RX),
what address does it use, and how does the hardware
understand it?

It uses a "buffer address". This is essentially an index into a "buffer-table" which is stored on the NIC. This table is used to lookup physical addresses that the NIC will DMA to/from.

The buffer-table is programmed from Dom0.

The buffer-table is effectively our IOMMU/page-tables.

Hope this helps,

Greg

--
Greg Law               glaw@xxxxxxxxxxxxxx              +44 1223 518 040

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

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