From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60482) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XlMw5-0006kB-9e for qemu-devel@nongnu.org; Mon, 03 Nov 2014 14:05:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XlMw1-0005vk-9p for qemu-devel@nongnu.org; Mon, 03 Nov 2014 14:05:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46240) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XlMw1-0005vg-3P for qemu-devel@nongnu.org; Mon, 03 Nov 2014 14:05:01 -0500 Date: Mon, 3 Nov 2014 19:04:48 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20141103190447.GE29967@work-vm> References: <1412358473-31398-1-git-send-email-dgilbert@redhat.com> <1412358473-31398-11-git-send-email-dgilbert@redhat.com> <20141103030550.GF8949@voom.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141103030550.GF8949@voom.redhat.com> Subject: Re: [Qemu-devel] [PATCH v4 10/47] Return path: Open a return path on QEMUFile for sockets List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Gibson Cc: aarcange@redhat.com, yamahata@private.email.ne.jp, quintela@redhat.com, cristian.klein@cs.umu.se, qemu-devel@nongnu.org, amit.shah@redhat.com, yanghy@cn.fujitsu.com * David Gibson (david@gibson.dropbear.id.au) wrote: > On Fri, Oct 03, 2014 at 06:47:16PM +0100, Dr. David Alan Gilbert (git) wrote: > > From: "Dr. David Alan Gilbert" > > > > Postcopy needs a method to send messages from the destination back to > > the source, this is the 'return path'. > > > > Wire it up for 'socket' QEMUFile's using a dup'd fd. > > This doesn't seem like the right abstraction to me. In particular I > can't really see how you'd implement this for anything other than > socket. > > I'd suggest instead creating new "open" helper functions (within the > QEMUFile code) that open both a forward and return path > simultaneously. Can you give an example of a transport where it would be a problem, so I can look at how that works? It's a little tricky since, on the destination, at the time we create the connection we don't know that we're going to need the return path. Dave > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK