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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 D8524C433ED for ; Fri, 30 Apr 2021 07:44:16 +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 6101D61449 for ; Fri, 30 Apr 2021 07:44:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6101D61449 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]:51636 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lcNot-0007Ar-AO for qemu-devel@archiver.kernel.org; Fri, 30 Apr 2021 03:44:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57660) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lcNn6-0006DJ-Gl for qemu-devel@nongnu.org; Fri, 30 Apr 2021 03:42:24 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:30670) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lcNn3-0000tV-Ln for qemu-devel@nongnu.org; Fri, 30 Apr 2021 03:42:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619768540; 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: in-reply-to:in-reply-to:references:references; bh=gJGX4c2vdR+l3iIt9nNLPh5PbvjNXAyaPw8aIJ1gqvM=; b=MQdiCqtBdugpHiGepukvJOIvmYwJvFQFHOGPgvXnvYrhcE8nte3gsaCZc9qIO+Gr0j3IXd 5AhdRaTxbxOpeLBpZPxEZvy8mZeSas04r2OrmmurWOUo1UGOY8tzDV1GMOk1qQvSJF05bX e1JZzRZ/wWqJ59Pn9iunODTC9XNeg/4= 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-157-TjQ2TbVPO3yqOjwayF7r8g-1; Fri, 30 Apr 2021 03:42:18 -0400 X-MC-Unique: TjQ2TbVPO3yqOjwayF7r8g-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8481E8186E8; Fri, 30 Apr 2021 07:42:16 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-114-17.ams2.redhat.com [10.36.114.17]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 97E39100EBAF; Fri, 30 Apr 2021 07:42:06 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 1CF98113525D; Fri, 30 Apr 2021 09:42:05 +0200 (CEST) From: Markus Armbruster To: Eduardo Habkost Subject: Re: [PATCH] virtio-blk: drop deprecated scsi=on|off property References: <20210429155221.1226561-1-stefanha@redhat.com> <20210429180352.ohhfz4kwyxapbiyl@habkost.net> Date: Fri, 30 Apr 2021 09:42:05 +0200 In-Reply-To: <20210429180352.ohhfz4kwyxapbiyl@habkost.net> (Eduardo Habkost's message of "Thu, 29 Apr 2021 14:03:52 -0400") Message-ID: <87lf905icy.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=216.205.24.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.22, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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 , qemu-block@nongnu.org, "Michael S. Tsirkin" , libvir-list@redhat.com, qemu-devel@nongnu.org, Max Reitz , Stefan Hajnoczi , Christoph Hellwig , "Dr . David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Eduardo Habkost writes: > On Thu, Apr 29, 2021 at 04:52:21PM +0100, Stefan Hajnoczi wrote: >> The scsi=on|off property was deprecated in QEMU 5.0 and can be removed >> completely at this point. >> >> Drop the scsi=on|off option. It was only available on Legacy virtio-blk >> devices. Linux v5.6 already dropped support for it. >> >> Remove the hw_compat_2_4[] property assignment since scsi=on|off no >> longer exists. Old guests with Legacy virtio-blk devices no longer see >> the SCSI host features bit. >> > > This means pc-2.4 will now break guest ABI if using virtio-blk > devices, correct? > > This looks like a sign we should have deprecated pc-2.4 a long > time ago. The last batch of PC machine type retiring was pc-1.0 to pc-1.3: deprecated in 5.0 (commit 30d2a17b4, Dec 2019), dropped in 6.0 (commit f862ddbb1, just weeks ago). pc-1.3 was a bit over seven years old when we released 5.0. pc-2.4 will be six years old by the time we release 6.1. Fair game? >> Live migrating old guests from an old QEMU with the SCSI feature bit >> enabled will fail with "Features 0x... unsupported. Allowed features: >> 0x...". We've followed the QEMU deprecation policy so users have been >> warned... >> > > Were they really warned, though? People running > "-machine pc-i440fx-2.4" might be completely unaware that it was > silently enabling a deprecated feature. We've gotten better at documenting deprecations, but we're still bad at warning on use of deprecated features. [...]