From mboxrd@z Thu Jan  1 00:00:00 1970
From: Christian Borntraeger <borntraeger@de.ibm.com>
Subject: Re: [PATCH 4/4] kvm-s390: onereg for timer related registers
Date: Tue, 05 Jun 2012 14:57:37 +0200
Message-ID: <4FCE0241.3000808@de.ibm.com>
References: <1337084128-38219-1-git-send-email-borntraeger@de.ibm.com> <1337084128-38219-5-git-send-email-borntraeger@de.ibm.com> <8300B56E-8A7F-4E4C-824C-307B6DC94521@suse.de>
Mime-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: Avi Kivity <avi@redhat.com>, Marcelo Tossati <mtosatti@redhat.com>,
	Carsten Otte <cotte@de.ibm.com>,
	Jens Freimann <jfrei@linux.vnet.ibm.com>,
	Cornelia Huck <cornelia.huck@de.ibm.com>,
	Heiko Carstens <heiko.carstens@de.ibm.com>,
	Martin Schwidefsky <schwidefsky@de.ibm.com>,
	Heinz Graalfs <graalfs@linux.vnet.ibm.com>,
	KVM <kvm@vger.kernel.org>, "Jason J. herne" <jjherne@us.ibm.com>
To: Alexander Graf <agraf@suse.de>
Return-path: <kvm-owner@vger.kernel.org>
Received: from e06smtp18.uk.ibm.com ([195.75.94.114]:42710 "EHLO
	e06smtp18.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751392Ab2FEM5o (ORCPT <rfc822;kvm@vger.kernel.org>);
	Tue, 5 Jun 2012 08:57:44 -0400
Received: from /spool/local
	by e06smtp18.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted
	for <kvm@vger.kernel.org> from <borntraeger@de.ibm.com>;
	Tue, 5 Jun 2012 13:57:41 +0100
Received: from d06av03.portsmouth.uk.ibm.com (d06av03.portsmouth.uk.ibm.com [9.149.37.213])
	by d06nrmr1507.portsmouth.uk.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q55CvcJp1872032
	for <kvm@vger.kernel.org>; Tue, 5 Jun 2012 13:57:39 +0100
Received: from d06av03.portsmouth.uk.ibm.com (localhost.localdomain [127.0.0.1])
	by d06av03.portsmouth.uk.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q55Cvbv1026333
	for <kvm@vger.kernel.org>; Tue, 5 Jun 2012 06:57:38 -0600
In-Reply-To: <8300B56E-8A7F-4E4C-824C-307B6DC94521@suse.de>
Sender: kvm-owner@vger.kernel.org
List-ID: <kvm.vger.kernel.org>

On 05/06/12 14:42, Alexander Graf wrote:
> 
> On 15.05.2012, at 14:15, Christian Borntraeger wrote:
> 
>> From: "Jason J. herne" <jjherne@us.ibm.com>
>>
>> Enhance the KVM ONE_REG capability within S390 to allow
>> getting/setting the following special cpu registers: clock comparator
>> and the cpu timer. These are needed for migration.
>>
>> Signed-off-by: Jason J. herne <jjherne@us.ibm.com>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> 
> Any other registers we need to expose to user space while we're at it? :)

I hope not. Life guest relocation prototyping indicates that we have at least
the subset that allows a linux guest to continue.

We might need a way for userspace to influence the output of the store
system information and store facility list instruction. Dont know, maybe
we could use ONEREG even for that purpose. Its on my todo list, but there
are too many other things to tidy up.

Since this would be interface/ABI I dont want to rush without really
understanding what I need for those instruction.

Christian