xen-devel

[Top] [All Lists]

[Xen-devel] Writing MSRs from Domain0

from [Holger Steinhaus]

[Permanent Link][Original]

To:	xen-devel@xxxxxxxxxxxxxxxxxxx
Subject:	[Xen-devel] Writing MSRs from Domain0
From:	Holger Steinhaus <hsteinhaus@xxxxxx>
Date:	Fri, 06 Oct 2006 11:11:16 +0200
Delivery-date:	Fri, 06 Oct 2006 02:11:47 -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>
Sender:	xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
User-agent:	Thunderbird 1.5.0.7 (X11/20060911)

Hello,

I recently tried Xen 3.0.3-testing on my 2x Opteron-244 SMP machine.
Everything works well exept one detail, which is not unimportant to me:
the powernow-k8 driver fails to switch frequencies. A closer look on the
powernow-k8 source reveals, that some MSR write operations seem to be
without any effect. A rdmsr() before and after the  wrmsr() call reveals
that no real change on the register ocurrs.

An older PowerNow patch from this list emulates MSR writes by DOM0_MSR
hypercalls, but this call seems to be abandoned some time ago. Other
routines in the kernel simply employ the rdmsr()/wrmsr() macros from the
Linux kernel, as the current PowerNow drivers does. Whats the correct
Xen-like way to maniputate a MSR from a Domain0?

Regards,
  Holger

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

[More with this subject...]

<Prev in Thread]	Current Thread	[Next in Thread>
[Xen-devel] Writing MSRs from Domain0, Holger Steinhaus <= Re: [Xen-devel] Writing MSRs from Domain0, Keir Fraser Re: [Xen-devel] Writing MSRs from Domain0, Holger Steinhaus Re: [Xen-devel] Writing MSRs from Domain0, Keir Fraser

Previous by Date:	Re: [Xen-devel] Building ioemu on NetBSD, Pierrick Brossin
Next by Date:	Re: [Xen-devel] Writing MSRs from Domain0, Keir Fraser
Previous by Thread:	[Xen-devel] reasons/requirements for some of patches/linux-2.6.16.29/, Jan Beulich*
Next by Thread:	Re: [Xen-devel] Writing MSRs from Domain0, Keir Fraser
Indexes:	[Date] [Thread] [Top] [All Lists]