From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:48555) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hF1FV-0008Iu-QJ for qemu-devel@nongnu.org; Fri, 12 Apr 2019 14:50:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hF1FS-0005gg-QG for qemu-devel@nongnu.org; Fri, 12 Apr 2019 14:50:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47384) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hF1FS-0005gF-GX for qemu-devel@nongnu.org; Fri, 12 Apr 2019 14:50:02 -0400 Date: Fri, 12 Apr 2019 19:49:56 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20190412184956.GT2906@work-vm> References: <20190412122028.7067-1-yury-kotov@yandex-team.ru> <20190412172309.GF25308@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline In-Reply-To: <20190412172309.GF25308@redhat.com> Content-Transfer-Encoding: quoted-printable 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: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Cc: Eric Blake , Yury Kotov , Juan Quintela , Markus Armbruster , Thomas Huth , Laurent Vivier , Paolo Bonzini , "open list:All patches CC here" , yc-core@yandex-team.ru * Daniel P. Berrang=E9 (berrange@redhat.com) wrote: > On Fri, Apr 12, 2019 at 12:13:51PM -0500, Eric Blake wrote: > > On 4/12/19 7:20 AM, Yury Kotov wrote: > > > Hi, > > >=20 > > > 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. > > >=20 > > > 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 migrati= on then it's > > > easier to send an fd with the migrate-* command. Also, client shoul= dn't maintain > > > this fd. > >=20 > > While the sentiment of making it easier by having fewer QMP commands > > might be worthwhile, I'm worried about whether this scales. Having ju= st > > 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 t= ake > > an fd inline. >=20 > 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". Yes, agreed - as you spotted passing fd's gets a bit hairy, and hence it's best to keep it to a few places. Lets figure out the right way of fixing the double-close you spotted rather than adding new schemes. Dave > Regards, > Daniel > --=20 > |: https://berrange.com -o- https://www.flickr.com/photos/dberr= ange :| > |: https://libvirt.org -o- https://fstop138.berrange= .com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberr= ange :| -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK 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=-2.4 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,T_HK_NAME_DR,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 43023C10F0E for ; Fri, 12 Apr 2019 18:51:13 +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 C844F20869 for ; Fri, 12 Apr 2019 18:51:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C844F20869 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]:41329 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hF1GZ-0000cE-OB for qemu-devel@archiver.kernel.org; Fri, 12 Apr 2019 14:51:11 -0400 Received: from eggs.gnu.org ([209.51.188.92]:48555) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hF1FV-0008Iu-QJ for qemu-devel@nongnu.org; Fri, 12 Apr 2019 14:50:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hF1FS-0005gg-QG for qemu-devel@nongnu.org; Fri, 12 Apr 2019 14:50:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47384) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hF1FS-0005gF-GX for qemu-devel@nongnu.org; Fri, 12 Apr 2019 14:50:02 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AF14D307AD02; Fri, 12 Apr 2019 18:50:01 +0000 (UTC) Received: from work-vm (unknown [10.36.117.255]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 585FA19C65; Fri, 12 Apr 2019 18:49:59 +0000 (UTC) Date: Fri, 12 Apr 2019 19:49:56 +0100 From: "Dr. David Alan Gilbert" To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Message-ID: <20190412184956.GT2906@work-vm> References: <20190412122028.7067-1-yury-kotov@yandex-team.ru> <20190412172309.GF25308@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline In-Reply-To: <20190412172309.GF25308@redhat.com> User-Agent: Mutt/1.11.4 (2019-03-13) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Fri, 12 Apr 2019 18:50:01 +0000 (UTC) Content-Transfer-Encoding: quoted-printable 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: , Cc: Laurent Vivier , Thomas Huth , Juan Quintela , Markus Armbruster , "open list:All patches CC here" , 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: <20190412184956.LNdIhvkGdDqncoDECir1w-J732lE8b7vAYTGaxwC_hI@z> * Daniel P. Berrang=E9 (berrange@redhat.com) wrote: > On Fri, Apr 12, 2019 at 12:13:51PM -0500, Eric Blake wrote: > > On 4/12/19 7:20 AM, Yury Kotov wrote: > > > Hi, > > >=20 > > > 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. > > >=20 > > > 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 migrati= on then it's > > > easier to send an fd with the migrate-* command. Also, client shoul= dn't maintain > > > this fd. > >=20 > > While the sentiment of making it easier by having fewer QMP commands > > might be worthwhile, I'm worried about whether this scales. Having ju= st > > 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 t= ake > > an fd inline. >=20 > 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". Yes, agreed - as you spotted passing fd's gets a bit hairy, and hence it's best to keep it to a few places. Lets figure out the right way of fixing the double-close you spotted rather than adding new schemes. Dave > Regards, > Daniel > --=20 > |: https://berrange.com -o- https://www.flickr.com/photos/dberr= ange :| > |: https://libvirt.org -o- https://fstop138.berrange= .com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberr= ange :| -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK