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=-5.3 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 5A51EC433DF for ; Mon, 3 Aug 2020 12:24:42 +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 23F5C207BB for ; Mon, 3 Aug 2020 12:24:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="axsUVxJU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 23F5C207BB 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 ([::1]:49544 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k2ZWE-0008Kv-A9 for qemu-devel@archiver.kernel.org; Mon, 03 Aug 2020 08:24:42 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33082) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k2ZVF-0007q8-Ra for qemu-devel@nongnu.org; Mon, 03 Aug 2020 08:23:41 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:51993 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1k2ZVE-0004M7-5b for qemu-devel@nongnu.org; Mon, 03 Aug 2020 08:23:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596457418; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=iJC4enJZXlhiXOaxUTdZok78zjEbK7o8qf8YqP+VnJg=; b=axsUVxJUnD/5/oohLrAb8AA60Qqk2UuaUHjkOn2rWYCo6XUPUtE5WvN7FIJDWIuTsB0e6I vnHSqLYbiikHjPKjKyczFNMWC8IilVOEprLxQt5gIaKntQnxwzjK6skFI8rUO0DViyICRE Nzo5IC0fL3vQ8ju8LBK2jppDwg89iTM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-338-DjNlfs1xNJeGmRt0bJk82w-1; Mon, 03 Aug 2020 08:23:26 -0400 X-MC-Unique: DjNlfs1xNJeGmRt0bJk82w-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 99DB71005504; Mon, 3 Aug 2020 12:23:25 +0000 (UTC) Received: from redhat.com (unknown [10.36.110.44]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D527D19C4F; Mon, 3 Aug 2020 12:23:07 +0000 (UTC) Date: Mon, 3 Aug 2020 13:23:04 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Paolo Bonzini Subject: Re: [PATCH] schemas: Add vim modeline Message-ID: <20200803122304.GJ3670709@redhat.com> References: <20200730093732.GB3477223@redhat.com> <87k0ylz0ep.fsf@dusky.pond.sub.org> <20200730132446.GL3477223@redhat.com> <875za33ku1.fsf@dusky.pond.sub.org> <20200731150738.GB3660103@redhat.com> <03bb7822-20a0-2945-6c86-1d5f1b2a01d9@redhat.com> <20200731154429.GD3660103@redhat.com> <21cda868-85d3-77db-31d8-0248a5029318@redhat.com> <20200803113655.GI3670709@redhat.com> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/1.14.5 (2020-06-23) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=205.139.110.61; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/03 02:56:11 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Eduardo Habkost , qemu-block@nongnu.org, "Michael S. Tsirkin" , qemu-devel@nongnu.org, Jason Wang , Juan Quintela , Yuval Shaia , Markus Armbruster , Gerd Hoffmann , Andrea Bolognani , =?utf-8?Q?Marc-Andr=C3=A9?= Lureau , John Snow , Michael Roth , "Dr. David Alan Gilbert" , Stefan Berger Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Aug 03, 2020 at 02:16:19PM +0200, Paolo Bonzini wrote: > On 03/08/20 13:36, Daniel P. Berrangé wrote: > >>> Given that QEMU needs to pass > >>> uint64 values, JSON was simply the wrong choice of format for QMP. > > > > I wasn't refering to RFC7159. The problem of undefined integer precision > > with JSON came up right at the very start when QMP was first designed and > > implemented, and has come up again periodically ever since then. libvirt > > needed to do workarounds right at the start in 2009, in order to fully > > handle signed/unsigned 64-bit integers with QMP. > > I assume the workaround you refer to is to store the number as a string > and converting it lazily to either an integer or a floating-point type > in whoever uses the JSON API. It may not be pretty but probably it > would have been the same for any text-based, schema-less protocol. For > example, it didn't require writing your own parser. Yes, we get the raw values as a string, but not all parsers for C allow you to do this. We'd really love to move off YAJL for JSON parsing, but the most viable alternatives don't have a way to let you get the string before they parse it as an integer and report errors. > It could be avoided by using a schema in Libvirt, just like QEMU has no > problem with it on the other side; it's just a different design choice > with different trade-offs, I don't think it's enough of an issue to > declare JSON "the wrong choice of format for QMP". The schema doesn't help - the problem is many JSON parsers don't allow use of full uint64 values when parsing - alot will simply report an error for anything bigger than LLONG_MAX and offer no workaround. 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 :|