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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id CEDD4C61DA4 for ; Thu, 9 Feb 2023 10:24:29 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pQ45t-0007XI-B5; Thu, 09 Feb 2023 05:23:57 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pQ45r-0007LF-Di for qemu-devel@nongnu.org; Thu, 09 Feb 2023 05:23:55 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pQ45p-0007D9-EI for qemu-devel@nongnu.org; Thu, 09 Feb 2023 05:23:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1675938232; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=PtDbNajDBDNaM54xmkHOW/QeT5tl8v6fNKGSvtPfacs=; b=TfEaRU8pKwbIFdSilMtpB/5gds9fUNZ2iKKwT8du0hn0zppDinbTxWlvgoR4Ox8m9U7tIn +yKlRNnflBm7Qg7QfFyVQ+OXbzSShGxgbIuNyzbKC2qMlkQ0isBTsORD0TRB+jCq2GTGXF rvA13kOVA42UU8yeeitS0ILzs2YP+/8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-176-c6Xdlk5dOEirfODHnfk9Mw-1; Thu, 09 Feb 2023 05:23:48 -0500 X-MC-Unique: c6Xdlk5dOEirfODHnfk9Mw-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2FC861869B6F; Thu, 9 Feb 2023 10:23:48 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.65]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6C39318EC1; Thu, 9 Feb 2023 10:23:46 +0000 (UTC) Date: Thu, 9 Feb 2023 10:23:43 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Eric Blake Cc: Het Gala , qemu-devel@nongnu.org, prerna.saxena@nutanix.com, quintela@redhat.com, dgilbert@redhat.com, pbonzini@redhat.com, armbru@redhat.com, manish.mishra@nutanix.com, aravind.retnakaran@nutanix.com Subject: Re: [PATCH v2 2/6] migration: Updated QAPI format for 'migrate' qemu monitor command Message-ID: References: <20230208093600.242665-1-het.gala@nutanix.com> <20230208093600.242665-3-het.gala@nutanix.com> <20230208201712.b3a5xtufscrvncqt@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230208201712.b3a5xtufscrvncqt@redhat.com> User-Agent: Mutt/2.2.9 (2022-11-12) X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Wed, Feb 08, 2023 at 02:17:12PM -0600, Eric Blake wrote: > On Wed, Feb 08, 2023 at 09:35:56AM +0000, Het Gala wrote: > > Existing 'migrate' QAPI design enforces transport mechanism, ip address > > of destination interface and corresponding port number in the form > > of a unified string 'uri' parameter for initiating a migration stream. > > This scheme has a significant flaw in it - double encoding of existing > > URIs to extract migration info. > > > > The current patch maps QAPI uri design onto well defined MigrateChannel > > struct. This modified QAPI helps in preventing multi-level uri > > encodings ('uri' parameter is kept for backward compatibility). > > > > Suggested-by: Daniel P. Berrange > > Suggested-by: Manish Mishra > > Suggested-by: Aravind Retnakaran > > Signed-off-by: Het Gala > > --- > > qapi/migration.json | 131 +++++++++++++++++++++++++++++++++++++++++++- > > 1 file changed, 129 insertions(+), 2 deletions(-) > > > > diff --git a/qapi/migration.json b/qapi/migration.json > > index c84fa10e86..79acfcfe4e 100644 > > --- a/qapi/migration.json > > +++ b/qapi/migration.json > > @@ -1449,12 +1449,108 @@ > > ## > > { 'command': 'migrate-continue', 'data': {'state': 'MigrationStatus'} } > > > > +## > > +# @MigrateTransport: > > +# > > +# The supported communication transport mechanisms for migration > > +# > > +# @socket: Supported communication type between two devices for migration. > > +# Socket is able to cover all of 'tcp', 'unix', 'vsock' and > > +# 'fd' already > > +# > > +# @exec: Supported communication type to redirect migration stream into file. > > +# > > +# @rdma: Supported communication type to redirect rdma type migration stream. > > +# > > +# Since 8.0 > > +## > > +{ 'enum': 'MigrateTransport', > > + 'data': ['socket', 'exec', 'rdma'] } > > + > > +## > > +# @MigrateSocketAddr: > > +# > > +# To support different type of socket. > > +# > > +# @socket-type: Different type of socket connections. > > +# > > +# Since 8.0 > > +## > > +{ 'struct': 'MigrateSocketAddr', > > + 'data': {'socket-type': 'SocketAddress' } } > > Here, you use 'socket-type',... > > > + > > +## > > +# @MigrateExecAddr: > > + # > > + # Since 8.0 > > + ## > > +{ 'struct': 'MigrateExecAddr', > > + 'data' : {'data': ['str'] } } > > Inconsistent on whether you have a space before :. Most of our qapi > files prefer the layout: > > 'key': 'value' > > that is, no space before, one space after. It doesn't affect > correctness, but a consistent visual style is worth striving for. > > > + > > +## > > +# @MigrateRdmaAddr: > > +# > > +# Since 8.0 > > +## > > +{ 'struct': 'MigrateRdmaAddr', > > + 'data' : {'data': 'InetSocketAddress' } } > > ...while these branches supply everything else under 'data'. Also, > while you documented @socket-type above, you did not document @data in > either of these two types. [1] > > > + > > +## > > +# @MigrateAddress: > > +# > > +# The options available for communication transport mechanisms for migration > > +# > > +# Since 8.0 > > +## > > +{ 'union' : 'MigrateAddress', > > + 'base' : { 'transport' : 'MigrateTransport'}, > > + 'discriminator' : 'transport', > > + 'data' : { > > + 'socket' : 'MigrateSocketAddr', > > + 'exec' : 'MigrateExecAddr', > > + 'rdma': 'MigrateRdmaAddr' } } > > Another example of inconsistent spacing around :. > > I'm guessing the reason you didn't go with 'socket': 'SocketAddress' > is that SocketAddress is itself a discriminated union, and Markus does > not yet have the QAPI generator wired up to support one union as a > branch of another larger union? It leads to extra nesting on the wire > [2] I don't know the backstory on this limitation. Is it something that is very difficult to resolve ? I think it is highly desirable to have 'socket': 'SocketAddress' here. It would be a shame to introduce this better migration API design and then have it complicated by a possibly short term limitation of QAPI. With 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 :|