From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35195) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zi2H8-0004ZL-R5 for qemu-devel@nongnu.org; Fri, 02 Oct 2015 11:29:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zi2H4-0004Yq-MY for qemu-devel@nongnu.org; Fri, 02 Oct 2015 11:29:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56463) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zi2H4-0004YB-GJ for qemu-devel@nongnu.org; Fri, 02 Oct 2015 11:29:30 -0400 Date: Fri, 2 Oct 2015 16:29:25 +0100 From: "Daniel P. Berrange" Message-ID: <20151002152925.GI28469@redhat.com> References: <1443515898-3594-1-git-send-email-dgilbert@redhat.com> <1443515898-3594-17-git-send-email-dgilbert@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1443515898-3594-17-git-send-email-dgilbert@redhat.com> Subject: Re: [Qemu-devel] [PATCH v8 16/54] Return path: Open a return path on QEMUFile for sockets Reply-To: "Daniel P. Berrange" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" Cc: aarcange@redhat.com, quintela@redhat.com, liang.z.li@intel.com, qemu-devel@nongnu.org, luis@cs.umu.se, bharata@linux.vnet.ibm.com, amit.shah@redhat.com, pbonzini@redhat.com On Tue, Sep 29, 2015 at 09:37:40AM +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. I find this to be a pretty wierd approach to the problem. THe underlying transport is bi-directional, so I would expect to have a single QEMUFile object that allowed bi-directional I/O on it, rather than creating a second QEMUFile for the back channel, which was forbidden from closing the shared FD. I can understand why you've done this though - since we only have a single buffer embedded in QEMUFile. I wonder though if we'd be better off changing QEMUFile to have a 'inbuf' and 'outbuf' intead of just 'buf' and likewise iniov & outiov. Then we can allow bi-directional I/O on the single QEMUFile object which is a more natural fit. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :|