From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58548C49ED6 for ; Mon, 9 Sep 2019 13:51:36 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3084D2086D for ; Mon, 9 Sep 2019 13:51:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3084D2086D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sipsolutions.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56978 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7K4t-0005oI-0W for qemu-devel@archiver.kernel.org; Mon, 09 Sep 2019 09:51:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34537) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7K4C-0005PB-Sr for qemu-devel@nongnu.org; Mon, 09 Sep 2019 09:50:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i7K4B-0008IE-TT for qemu-devel@nongnu.org; Mon, 09 Sep 2019 09:50:52 -0400 Received: from s3.sipsolutions.net ([2a01:4f8:191:4433::2]:47682 helo=sipsolutions.net) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i7K4B-0008Fv-N5 for qemu-devel@nongnu.org; Mon, 09 Sep 2019 09:50:51 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1i7K49-0005fg-DL; Mon, 09 Sep 2019 15:50:49 +0200 Message-ID: From: Johannes Berg To: "Michael S. Tsirkin" Date: Mon, 09 Sep 2019 15:50:48 +0200 In-Reply-To: <20190909094609-mutt-send-email-mst@kernel.org> References: <20190902121233.13382-1-johannes@sipsolutions.net> <20190906121350.29202-1-johannes@sipsolutions.net> <20190906102217-mutt-send-email-mst@kernel.org> <20190906110340-mutt-send-email-mst@kernel.org> <20190908091207-mutt-send-email-mst@kernel.org> <8a9cf8a1726afce7fed8992a4f19fc808004ef88.camel@sipsolutions.net> <20190909083902-mutt-send-email-mst@kernel.org> <89f25546ffa71c799c533e50658a3a58e066f436.camel@sipsolutions.net> <20190909094609-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.30.5 (3.30.5-1.fc29) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a01:4f8:191:4433::2 Subject: Re: [Qemu-devel] [RFC] libvhost-user: implement VHOST_USER_PROTOCOL_F_KICK_CALL_MSGS X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, 2019-09-09 at 09:48 -0400, Michael S. Tsirkin wrote: > > I suppose we could fail a later command that already needs a reply > > without REPLY_ACK, but that seems difficult to debug? > > Next command is GET_FEATURES. Return an error response from that > and device init will fail. Hmm, what's an error here though? You can only return a value, no? > > Anyway, if you feel that we should have this as some sort of safeguard I > > can try to do that; to me it feels rather pointless as libvhost-user is > > more of a sample implementation than anything else. > > Exactly for this reason :) :) > > Unless you also wanted to write into the spec that F_KICK_CALL_MSGS > > absolutely *requires* F_REPLY_ACK, > > yep Sure, I'm fine with that. > We can document how to behave in case of inconsistent protocol features, > yes. OK. johannes