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] Fam10+ extended config space enabling

To: <robert.richter@xxxxxxx>
Subject: [Xen-devel] Fam10+ extended config space enabling
From: "Jan Beulich" <JBeulich@xxxxxxxxxx>
Date: Thu, 06 Jan 2011 10:15:06 +0000
Cc: "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>
Delivery-date: Thu, 06 Jan 2011 02:16:05 -0800
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

starting with 2.6.27 Linux is doing this, using MSR accesses (these
days in CPU hotplug notification callbacks). Is there a reason this
cannot be done through PCI config space writes (as the register is
aliased), and then only once at boot time (perhaps utilizing some
of the code in arch/x86/kernel/k8.c)?

I'm particularly asking from the Xen perspective, where the MSR
based mechanism won't reliably work (since there's no guarantee
all of Dom0's virtual CPUs would, at initialization time, actually
cover all physical CPUs that Dom0 may ever run on).

Thanks, Jan

Xen-devel mailing list