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

[Xen-devel] [PATCH] [HVM][SVM] Handle threshold register for guests

To: xen-devel@xxxxxxxxxxxxxxxxxxx
Subject: [Xen-devel] [PATCH] [HVM][SVM] Handle threshold register for guests
From: "Christoph Egger" <Christoph.Egger@xxxxxxx>
Date: Mon, 21 May 2007 19:24:55 +0200
Delivery-date: Mon, 21 May 2007 10:23:38 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
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>
Organization: AMD / OSRC
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: KMail/1.9.6
Hi!

The threshold register has been introduced in AMD RevF CPUs along with SVM
(Actually this MCA/MCE msr register existed before, but had no meaning).
Therefore no need for additional cpuid checks.

On read access it reports the HVM guest the register has been locked by the 
BIOS. This means, it is not available for OS use. Thus, write accesses are
simply ignored.
This behaviour actually matches real HW, so guests can deal with this.

Further, this way no multiplexing for multiple guests is necessary.
Please apply.

Signed off by: Christoph Egger <Christoph.Egger@xxxxxxx>


-- 
AMD Saxony, Dresden Germany
Operating System Research Center

Legal Information:
AMD Saxony Limited Liability Company & Co. KG
Sitz (Geschäftsanschrift):
   Wilschdorfer Landstr. 101, 01109 Dresden, Deutschland
Registergericht Dresden: HRA 4896
vertretungsberechtigter Komplementär:
   AMD Saxony LLC (Sitz Wilmington, Delaware, USA)
Geschäftsführer der AMD Saxony LLC:
   Dr. Hans-R. Deppe, Thomas McCoy

Attachment: xen_threshold.diff
Description: Text Data

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