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] Re: Question regarding VM_EXIT and VGA

To: Sujata Garera <sujatadoshi@xxxxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>, Ryan Gardner <ryan@xxxxxxxxxx>
Subject: Re: [Xen-devel] Re: Question regarding VM_EXIT and VGA
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Mon, 22 Oct 2007 19:44:16 +0100
Delivery-date: Mon, 22 Oct 2007 11:40:12 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <47a91af40710221046x7ffcac79rb6af3f4df3d888bd@xxxxxxxxxxxxxx>
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>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
Thread-index: AcgU24wLyocZJoDOEdyItAAWy6hiGQ==
Thread-topic: [Xen-devel] Re: Question regarding VM_EXIT and VGA
User-agent: Microsoft-Entourage/11.3.6.070618
That patch is now in the xen-unstable repository.

 -- Keir

On 22/10/07 18:46, "Sujata Garera" <sujatadoshi@xxxxxxxxx> wrote:

Hi,

I'm a student working on a research project using xen, and part of
what we are doing requires the ability to use the branch tracing
facilities of the processor.  I.e. we need to be able to write to the
IA32_DEBUGCTL MSR and read from the Last Branch Record (LBR) stack
(the second of which it appears we can do).

We saw a thread discussing this:
http://lists.xensource.com/archives/html/xen-devel/2007-08/msg00198.html
.  However, it doesn't appear that the method was ever finalized, and
we were unable to find a patch.  Does such a patch exist, or is there
simple way we can read and write to the necessary MSRs in our VM?  Can
we just hack the xen code to set the correct bits in the VMCS MSR
bitmaps?  If so, where are those bitmaps set in the code?

Thanks a lot.

Sujata



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

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel
<Prev in Thread] Current Thread [Next in Thread>