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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 B5577C433B4 for ; Thu, 29 Apr 2021 18:06:10 +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 053056101E for ; Thu, 29 Apr 2021 18:06:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 053056101E 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]:59040 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lcB3A-0007vb-Mx for qemu-devel@archiver.kernel.org; Thu, 29 Apr 2021 14:06:08 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44420) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lcB1L-00070n-UJ for qemu-devel@nongnu.org; Thu, 29 Apr 2021 14:04:15 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:27755) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lcB1F-00038E-BQ for qemu-devel@nongnu.org; Thu, 29 Apr 2021 14:04:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619719448; 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=kjDS+KrbfFoM5P37fRkEddgeJmivGpq36JSQRKXg1KY=; b=Q6AwjIBchi5AO6ZCizvJi0KnbprYsDnsLFHxOImgjKWLK8VLdjmXBhoW2NVy6EFrPJlytI 6Ivx2PSXgqgyneYUOXh6WpOm4XsqpL1FNqH/8EO5qXNLUusLHyD8BqRWx7h8jqrc6tiy4U 9jiJVSN+Y2UMK0D28W2QSZhsZ+VXKO4= 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-582-oHloBzMCPbGMR4ypzMWYmQ-1; Thu, 29 Apr 2021 14:04:04 -0400 X-MC-Unique: oHloBzMCPbGMR4ypzMWYmQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 334071006C87; Thu, 29 Apr 2021 18:04:03 +0000 (UTC) Received: from localhost (ovpn-115-66.phx2.redhat.com [10.3.115.66]) by smtp.corp.redhat.com (Postfix) with ESMTP id 86A4F5B6A2; Thu, 29 Apr 2021 18:03:53 +0000 (UTC) Date: Thu, 29 Apr 2021 14:03:52 -0400 From: Eduardo Habkost To: Stefan Hajnoczi Subject: Re: [PATCH] virtio-blk: drop deprecated scsi=on|off property Message-ID: <20210429180352.ohhfz4kwyxapbiyl@habkost.net> References: <20210429155221.1226561-1-stefanha@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210429155221.1226561-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=ehabkost@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=unavailable 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, Markus Armbruster , qemu-devel@nongnu.org, Max Reitz , Christoph Hellwig , "Dr . David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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. > 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. Can we have this documented in a more explicit way? Maybe just a comment at hw_compat_2_4 would be enough, to warn people doing backports and rebases downstream. Can we make QEMU refuse to start if using pc-2.4 + virtio-blk together, just to be sure? An alternative would be keeping the property (and the hw_compat_2_4 entry) just to keep pc-2.4 working (until pc-2.4 is deprecated and removed), but refusing to realize the device if the feature is enabled. > I have tested that libvirt still works when the property is absent. It > no longer adds scsi=on|off to the command-line. > > Cc: Markus Armbruster > Cc: Christoph Hellwig > Cc: Peter Krempa > Cc: Dr. David Alan Gilbert > Signed-off-by: Stefan Hajnoczi > --- [...] > diff --git a/hw/core/machine.c b/hw/core/machine.c > index 40def78183..286f18ec6d 100644 > --- a/hw/core/machine.c > +++ b/hw/core/machine.c > @@ -194,8 +194,6 @@ GlobalProperty hw_compat_2_5[] = { > const size_t hw_compat_2_5_len = G_N_ELEMENTS(hw_compat_2_5); > > GlobalProperty hw_compat_2_4[] = { > - /* Optional because the 'scsi' property is Linux-only */ > - { "virtio-blk-device", "scsi", "true", .optional = true }, > { "e1000", "extra_mac_registers", "off" }, > { "virtio-pci", "x-disable-pcie", "on" }, > { "virtio-pci", "migrate-extra", "off" }, -- Eduardo