From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:52237) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fQI24-0007FC-CL for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:54:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fQI23-0004Xs-Hm for qemu-devel@nongnu.org; Tue, 05 Jun 2018 15:54:16 -0400 References: <20180524113251.GB4660@redhat.com> <20180528183058.GG2209@redhat.com> <20180528183833.GJ4580@localhost.localdomain> <20180528212054.GH2209@redhat.com> <20180528212510.GC4660@redhat.com> <20180529064415.GA4756@localhost.localdomain> <2b3eef00-f326-c1e6-0e4b-b7602646eec4@redhat.com> <20180605092159.GA2544@work-vm> <20180605190324.GA11372@localhost.localdomain> <20180605223934-mutt-send-email-mst@kernel.org> From: Eric Blake Message-ID: Date: Tue, 5 Jun 2018 14:54:07 -0500 MIME-Version: 1.0 In-Reply-To: <20180605223934-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [Qemu-block] storing machine data in qcow images? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" , Eduardo Habkost Cc: Kevin Wolf , qemu-block@nongnu.org, qemu-devel@nongnu.org, "Richard W.M. Jones" , stefanha@redhat.com, Max Reitz , "Dr. David Alan Gilbert" On 06/05/2018 02:47 PM, Michael S. Tsirkin wrote: >>> Layer 1: >>> The string shall always be a JSON 'object'; i.e. of the form >>> { "something": ... , "more": ... } >>> >>> The key strings shall be non-null and non-empty and shall >>> be unique. >> >> I think it would be simpler if layer 0 simply provided a list of >> names/value pairs, where names are ascii strings, and values are >> binary data[1]. It would make layer 1 unnecessary, and allow (3) >> and (4) to happen. >> >> [1] In other words, Rich's proposal of "named blobs": >> https://www.mail-archive.com/qemu-block@nongnu.org/msg37856.html > > I think simple is beautiful, too. But assuming they > really are binary how are blobs encoded? > Did binary really mean UTF-8 here? Binary blobs can always be base64 encoded for representation within a valid JSON UTF-8 string (and we already have several QMP interfaces that utilize base64 encoding to pass through what is otherwise invalid UTF-8). It does inflate things slightly compared to a format that allows a raw length coupled with raw data, but that is not necessarily a problem. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3266 Virtualization: qemu.org | libvirt.org