From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46965) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y0VyE-0008KK-7s for qemu-devel@nongnu.org; Mon, 15 Dec 2014 08:46:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y0Vy6-00013x-6K for qemu-devel@nongnu.org; Mon, 15 Dec 2014 08:45:54 -0500 Message-ID: <548EE600.9010307@redhat.com> Date: Mon, 15 Dec 2014 14:45:36 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <1418388243-1886-1-git-send-email-pbonzini@redhat.com> <1418388243-1886-2-git-send-email-pbonzini@redhat.com> <20141215104620.GB5502@work-vm> <548ECB56.6020901@redhat.com> <20141215133030.GD5502@work-vm> <548EE361.605@redhat.com> <20141215133719.GE5502@work-vm> In-Reply-To: <20141215133719.GE5502@work-vm> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 1/4] serial: reset thri_pending on IER writes with THRI=0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: imammedo@redhat.com, batuzovk@ispras.ru, andrey@xdel.ru, qemu-stable@nongnu.org, qemu-devel@nongnu.org On 15/12/2014 14:37, Dr. David Alan Gilbert wrote: >> > Right, the question is whether you really want to do this. :) > Well, it would solve this type of problem less painfully, your migration > would always succeed and destinations that knew what to do with it would > always do the right thing. Yes, that's a determination to make. I agree that this particular case is one where losing the subsection is not the end of the world, and keying off the machine type could be a good call for downstreams. But that's also because downstreams can also patch older source versions, while QEMU will not release another 2.1 version. In fact... > Of course you could also solve the problem > if the source knew the version of the destination, but you didn't like > that idea either. ... if the source could be patched by someone to know the version of the destination, they could also add the subsection with a "needed" function that always returns 0. This way it is never migrated, but it is interpreted. You do not need the version of the destination. Paolo