From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH 0/9] S390x KVM support Date: Thu, 22 Oct 2009 11:53:18 +0200 Message-ID: <4AE02B8E.6070202@redhat.com> References: <1255963059-10298-1-git-send-email-agraf@suse.de> <4ADDE7E3.9090601@de.ibm.com> <4AE0210D.9020409@redhat.com> <98DC9E4C-7FFA-4F05-A2E8-0B5DF546891C@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Carsten Otte , qemu-devel , uli@suse.de, Carsten Otte , hare@suse.de, KVM list To: Alexander Graf Return-path: Received: from mx1.redhat.com ([209.132.183.28]:21945 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752100AbZJVJxV (ORCPT ); Thu, 22 Oct 2009 05:53:21 -0400 In-Reply-To: <98DC9E4C-7FFA-4F05-A2E8-0B5DF546891C@suse.de> Sender: kvm-owner@vger.kernel.org List-ID: On 10/22/2009 11:11 AM, Alexander Graf wrote: >> Doesn't this break backward compatibility by changing the structure? >> >> Best to put it after the union (and as a copy, so userspace that >> expects the previous location still works). If you're reading it >> from the kernel, also need a way to tell the kernel which copy to >> read from. >> >> Also advertise with a KVM_CAP. > > > I don't think we need to go through the hassle here. There is > effectively no user of that code for now and the ABI is considered > unstable. At the very least we need a KVM_CAP so qemu knows to fail on older kernels. >> >> I'd also appreciate an explanation of what this is all about. > > Explanation in the code or explanation in an email reply? email. I assume s390 hackers would understand why the psw needs to be exposed to qemu on every exit. This is mostly for my personal interest. -- error compiling committee.c: too many arguments to function