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 6CB8BC4740A for ; Mon, 9 Sep 2019 11:36:10 +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 430DB218AF for ; Mon, 9 Sep 2019 11:36:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 430DB218AF 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]:55286 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7Hxp-0003CK-Er for qemu-devel@archiver.kernel.org; Mon, 09 Sep 2019 07:36:09 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:40186) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i7Hx9-0002kQ-5b for qemu-devel@nongnu.org; Mon, 09 Sep 2019 07:35:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i7Hx8-0005EJ-01 for qemu-devel@nongnu.org; Mon, 09 Sep 2019 07:35:26 -0400 Received: from s3.sipsolutions.net ([2a01:4f8:191:4433::2]:45268 helo=sipsolutions.net) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i7Hx7-000520-Pd for qemu-devel@nongnu.org; Mon, 09 Sep 2019 07:35:25 -0400 Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1i7Hx3-0002Oj-VH; Mon, 09 Sep 2019 13:35:22 +0200 Message-ID: <8a9cf8a1726afce7fed8992a4f19fc808004ef88.camel@sipsolutions.net> From: Johannes Berg To: "Michael S. Tsirkin" Date: Mon, 09 Sep 2019 13:35:19 +0200 In-Reply-To: <20190908091207-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> 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 Sun, 2019-09-08 at 09:13 -0400, Michael S. Tsirkin wrote: > > I think the only use for this extension would be for simulation > > purposes, and even then only combined with the REPLY_ACK and SLAVE_REQ > > extensions, i.e. you explicitly *want* your virtual machine to lock up / > > wait for a response to the KICK command (and respectively, the device to > > wait for a response to the CALL command). > > OK so when combined with these, it's OK I think. OK. > Do we want to force this restriction in code maybe then? Unlike in this patch, I was planning to not actually advertise VHOST_USER_PROTOCOL_F_KICK_CALL_MSGS, and do that only if the user of the library wants to advertise it, since devices used for simulation also have to be careful about how they use this. However, if I understand correctly we cannot enforce that all of them are used at the same time - we're the device side, so we only advertise our features and the master actually sets the ones it wants to use, no? The only thing we could do is crash if it wants to use this feature without the others, but would that really be helpful? I'm starting to actually get this working, so I'll post new patches in a few days or so. johannes