From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55061) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ze00a-0005tL-PE for qemu-devel@nongnu.org; Mon, 21 Sep 2015 08:15:49 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Ze00X-0007T5-C1 for qemu-devel@nongnu.org; Mon, 21 Sep 2015 08:15:48 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53452) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Ze00X-0007Sq-6S for qemu-devel@nongnu.org; Mon, 21 Sep 2015 08:15:45 -0400 References: <20150831160655-mutt-send-email-mst@redhat.com> <55ED854A.1080804@huawei.com> <55EFF03A.4000109@huawei.com> <55FC3BE7.5010503@huawei.com> <55FC7DFA.80204@redhat.com> <55FFE03E.6080106@siemens.com> From: Paolo Bonzini Message-ID: <55FFF4ED.4000908@redhat.com> Date: Mon, 21 Sep 2015 14:15:41 +0200 MIME-Version: 1.0 In-Reply-To: <55FFE03E.6080106@siemens.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] RFC: virtio-peer shared memory based peer communication device List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka , Claudio Fontana , "Zhang, Yang Z" , "Michael S. Tsirkin" , "qemu-devel@nongnu.org" , "virtualization@lists.linux-foundation.org" , "virtio-dev@lists.oasis-open.org" , "opnfv-tech-discuss@lists.opnfv.org" On 21/09/2015 12:47, Jan Kiszka wrote: >> > Apart from the windows idea, how does virtio-peer compare to virtio-= rpmsg? > rpmsg is a very specialized thing. It targets single AMP cores, assumin= g > that those have full access to the main memory. Yes, this is why I did say "apart from the windows idea". > And it is also a > centralized approach where all message go through the main Linux > instance. I suspect we could cover that use case as well with generic > inter-vm shared memory device, but I didn't think about all details yet= . The virtqueue handling seems very similar between the two. However, the messages for rpmsg however have a small header (struct rpmsg_hdr in include/linux/rpmsg.h) and there is a weird feature bit VIRTIO_RPMSG_F_NS= . So I guess virtio-rpmsg and virtio-peer are about as similar as virtio-serial and virtio-peer. Paolo