From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49223) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XFlgN-0000L8-AF for qemu-devel@nongnu.org; Fri, 08 Aug 2014 11:02:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XFlgE-00069m-9S for qemu-devel@nongnu.org; Fri, 08 Aug 2014 11:02:15 -0400 Received: from mail-wg0-x229.google.com ([2a00:1450:400c:c00::229]:60971) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XFlgE-00069a-2E for qemu-devel@nongnu.org; Fri, 08 Aug 2014 11:02:06 -0400 Received: by mail-wg0-f41.google.com with SMTP id z12so5801203wgg.24 for ; Fri, 08 Aug 2014 08:02:05 -0700 (PDT) Date: Fri, 8 Aug 2014 16:02:02 +0100 From: Stefan Hajnoczi Message-ID: <20140808150202.GD13382@stefanha-thinkpad.redhat.com> References: <1407488118-11245-1-git-send-email-david.marchand@6wind.com> <1407488118-11245-3-git-send-email-david.marchand@6wind.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="BRE3mIcgqKzpedwo" Content-Disposition: inline In-Reply-To: <1407488118-11245-3-git-send-email-david.marchand@6wind.com> Subject: Re: [Qemu-devel] [PATCH v3 2/2] docs: update ivshmem device spec List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Marchand Cc: kvm@vger.kernel.org, claudio.fontana@huawei.com, qemu-devel@nongnu.org, armbru@redhat.com, pbonzini@redhat.com, jani.kokkonen@huawei.com, cam@cs.ualberta.ca --BRE3mIcgqKzpedwo Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Aug 08, 2014 at 10:55:18AM +0200, David Marchand wrote: > +For each client (QEMU processes) that connects to the server: > +- the server assigns an ID for this client and sends this ID to him as the first > + message, > +- the server sends a fd to the shared memory object to this client, > +- the server creates a new set of host eventfds associated to the new client and > + sends this set to all already connected clients, > +- finally, the server sends all the eventfds sets for all clients to the new > + client. The protocol is not extensible and no version number is exchanged. For the most part this should be okay because clients must run on the same machine as the server. It is assumed clients and server are compatible with each other. I wonder if we'll get into trouble later if the protocol needs to be extended or some operation needs to happen, like upgrading QEMU or the ivshmem-server. At the very least someone building from source but using system QEMU or ivshmem-server could get confusing failures if the protocol doesn't match. How about sending a version message as the first thing during a connection? Stefan --BRE3mIcgqKzpedwo Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQEcBAEBAgAGBQJT5OZqAAoJEJykq7OBq3PIflkH/iyY9WqKQXduhJ60r9RQJA/5 v20frsL0f0mnazYjs9pU4BBqL7Q3xHWlHTT5dSo79seg/CE5HEc51hnSvKzsrklo xkG2Hl4o8k+IIJ1CCV274b3eRq9wSBBhJ/q9lVcyEgriwlvuCD5yQx8IMgvXP7G+ Iy2G/uSYaxBmm6OQXaMZA37S0SI8OC0N+h8WNpeKY7W42izzAJ+fT+56HYSVVwBq o2CE+Foej81SyoF7P5uSAxM1E/XuUtLG3nRdt1rDAeWJEOov2mK161CyFKBTEhJn bJMz1EGLJ3wRsOIc044O139gaLHN/OQ6sKEwnEdfY9Q15T2pb2cJgDVX3jRsFyM= =7oqY -----END PGP SIGNATURE----- --BRE3mIcgqKzpedwo--