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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A, 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 621E6C433ED for ; Mon, 3 May 2021 18:23:01 +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 C127A610A7 for ; Mon, 3 May 2021 18:23:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C127A610A7 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]:35924 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lddDf-00088i-OF for qemu-devel@archiver.kernel.org; Mon, 03 May 2021 14:22:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36790) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lddCm-0007jZ-OK for qemu-devel@nongnu.org; Mon, 03 May 2021 14:22:04 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42025) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lddCj-0008RH-Re for qemu-devel@nongnu.org; Mon, 03 May 2021 14:22:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1620066119; h=from:from: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=s4HVq9k6OLgO5YfEk0vVF6cynWG4X0k6OKoVyLRdkgs=; b=SWRCnDXMu85QkMQK9oBpWp7y2HQYIkJQ+KUBlpjXQZcWoIkPu8oXiztNIdx57J71yg23M9 Fk14mHZXcXajPn6XaI956kAOsr1WWIfr2R1h5xRnIv3KWQma2LK4ywdepnBPeThqeNIIWf POwO5psos0zj6q8jJFlwkrqWAPW00sc= 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-306-QJ_K76P2M-ufgEFBXWUFAA-1; Mon, 03 May 2021 14:21:55 -0400 X-MC-Unique: QJ_K76P2M-ufgEFBXWUFAA-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 96E669F92A for ; Mon, 3 May 2021 18:21:53 +0000 (UTC) Received: from [10.3.114.144] (ovpn-114-144.phx2.redhat.com [10.3.114.144]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6C7145C1D0; Mon, 3 May 2021 18:21:48 +0000 (UTC) Subject: Re: Let's remove some deprecated stuff To: Markus Armbruster , qemu-devel@nongnu.org References: <87y2d1csxe.fsf@dusky.pond.sub.org> From: Eric Blake Organization: Red Hat, Inc. Message-ID: Date: Mon, 3 May 2021 13:21:47 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <87y2d1csxe.fsf@dusky.pond.sub.org> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.698, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Peter Krempa , "libvirt-list@redhat.com" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 4/29/21 4:59 AM, Markus Armbruster wrote: > If you're cc'ed, you added a section to docs/system/deprecated.rst that > is old enough to permit removal. This is *not* a demand to remove, it's > a polite request to consider whether the time for removal has come. > Extra points for telling us in a reply. "We should remove, but I can't > do it myself right now" is a valid answer. Let's review the file: > [adjusting cc for this response] > > Eric Blake: > > qemu-img amend to adjust backing file (since 5.1) > ''''''''''''''''''''''''''''''''''''''''''''''''' > > The use of ``qemu-img amend`` to modify the name or format of a qcow2 > backing image is deprecated; this functionality was never fully > documented or tested, and interferes with other amend operations that > need access to the original backing image (such as deciding whether a > v3 zero cluster may be left unallocated when converting to a v2 > image). Rather, any changes to the backing chain should be performed > with ``qemu-img rebase -u`` either before or after the remaining > changes being performed by amend, as appropriate. > > qemu-img backing file without format (since 5.1) > '''''''''''''''''''''''''''''''''''''''''''''''' > > The use of ``qemu-img create``, ``qemu-img rebase``, or ``qemu-img > convert`` to create or modify an image that depends on a backing file > now recommends that an explicit backing format be provided. This is > for safety: if QEMU probes a different format than what you thought, > the data presented to the guest will be corrupt; similarly, presenting > a raw image to a guest allows a potential security exploit if a future > probe sees a non-raw image based on guest writes. > > To avoid the warning message, or even future refusal to create an > unsafe image, you must pass ``-o backing_fmt=`` (or the shorthand > ``-F`` during create) to specify the intended backing format. You may > use ``qemu-img rebase -u`` to retroactively add a backing format to an > existing image. However, be aware that there are already potential > security risks to blindly using ``qemu-img info`` to probe the format > of an untrusted backing image, when deciding what format to add into > an existing image. I'm not sure how widely used these were, but I'm game for writing a patch to drop them. I'm fairly certain libvirt is not using them. > > Kevin Wolf: > > ``nbd-server-add`` and ``nbd-server-remove`` (since 5.2) > '''''''''''''''''''''''''''''''''''''''''''''''''''''''' > > Use the more generic commands ``block-export-add`` and ``block-export-del`` > instead. As part of this deprecation, where ``nbd-server-add`` used a > single ``bitmap``, the new ``block-export-add`` uses a list of ``bitmaps``. Peter, is libvirt good for this one to go? -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org