From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:60400) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEztW-0002mL-S8 for qemu-devel@nongnu.org; Fri, 12 Apr 2019 13:23:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hEztV-0004kv-Ft for qemu-devel@nongnu.org; Fri, 12 Apr 2019 13:23:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9162) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hEztV-0004kb-7w for qemu-devel@nongnu.org; Fri, 12 Apr 2019 13:23:17 -0400 Date: Fri, 12 Apr 2019 18:23:09 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20190412172309.GF25308@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20190412122028.7067-1-yury-kotov@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH 0/3] Add 'inline-fd:' protocol for migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Blake Cc: Yury Kotov , Juan Quintela , "Dr. David Alan Gilbert" , Markus Armbruster , Thomas Huth , Laurent Vivier , Paolo Bonzini , "open list:All patches CC here" , yc-core@yandex-team.ru On Fri, Apr 12, 2019 at 12:13:51PM -0500, Eric Blake wrote: > On 4/12/19 7:20 AM, Yury Kotov wrote: > > Hi, > > > > I've added 'inline-fd:' proto to simplify migration to/from fd. > > I thought about modifying the existing 'fd:' proto but I'm not sure it's a > > good idea to change it's contract. > > > > Existing 'fd:' proto works with previously added fd by getfd or add-fd commands. > > If client doesn't want to work with this fd before or after migration then it's > > easier to send an fd with the migrate-* command. Also, client shouldn't maintain > > this fd. > > While the sentiment of making it easier by having fewer QMP commands > might be worthwhile, I'm worried about whether this scales. Having just > a limited set of commands that take an fd over SCM rights, and every > other command wired to automagically work with existing named fds, > scales a lot easier than having to teach individual commands how to take > an fd inline. Yeah I tend to agree - we use FD passing extensively across QMP/HMP and all these commands are written to interact with "getfd". I think it would be a step backwards to introduce a special case with migration that doesn't use "getfd". Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| 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=-2.3 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_MUTT autolearn=ham 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 D89F9C10F0E for ; Fri, 12 Apr 2019 17:24:09 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7A7E420652 for ; Fri, 12 Apr 2019 17:24:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A7E420652 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([127.0.0.1]:40426 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEzuK-00036j-Kh for qemu-devel@archiver.kernel.org; Fri, 12 Apr 2019 13:24:08 -0400 Received: from eggs.gnu.org ([209.51.188.92]:60400) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hEztW-0002mL-S8 for qemu-devel@nongnu.org; Fri, 12 Apr 2019 13:23:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hEztV-0004kv-Ft for qemu-devel@nongnu.org; Fri, 12 Apr 2019 13:23:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9162) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hEztV-0004kb-7w for qemu-devel@nongnu.org; Fri, 12 Apr 2019 13:23:17 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 74C54811D5; Fri, 12 Apr 2019 17:23:16 +0000 (UTC) Received: from redhat.com (ovpn-112-27.ams2.redhat.com [10.36.112.27]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 1CDA61001E81; Fri, 12 Apr 2019 17:23:12 +0000 (UTC) Date: Fri, 12 Apr 2019 18:23:09 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Eric Blake Message-ID: <20190412172309.GF25308@redhat.com> References: <20190412122028.7067-1-yury-kotov@yandex-team.ru> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.3 (2019-02-01) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Fri, 12 Apr 2019 17:23:16 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [PATCH 0/3] Add 'inline-fd:' protocol for migration X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Laurent Vivier , Thomas Huth , Juan Quintela , "open list:All patches CC here" , Markus Armbruster , "Dr. David Alan Gilbert" , Yury Kotov , yc-core@yandex-team.ru, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Message-ID: <20190412172309.Qey6-kBtb0SdehC4L0k2UoIyk80npTC-Y5_r2ZSfWoA@z> On Fri, Apr 12, 2019 at 12:13:51PM -0500, Eric Blake wrote: > On 4/12/19 7:20 AM, Yury Kotov wrote: > > Hi, > > > > I've added 'inline-fd:' proto to simplify migration to/from fd. > > I thought about modifying the existing 'fd:' proto but I'm not sure it's a > > good idea to change it's contract. > > > > Existing 'fd:' proto works with previously added fd by getfd or add-fd commands. > > If client doesn't want to work with this fd before or after migration then it's > > easier to send an fd with the migrate-* command. Also, client shouldn't maintain > > this fd. > > While the sentiment of making it easier by having fewer QMP commands > might be worthwhile, I'm worried about whether this scales. Having just > a limited set of commands that take an fd over SCM rights, and every > other command wired to automagically work with existing named fds, > scales a lot easier than having to teach individual commands how to take > an fd inline. Yeah I tend to agree - we use FD passing extensively across QMP/HMP and all these commands are written to interact with "getfd". I think it would be a step backwards to introduce a special case with migration that doesn't use "getfd". Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|