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=-0.6 required=3.0 tests=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 B73D9C43331 for ; Wed, 1 Apr 2020 11:14:31 +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 7EE31206E9 for ; Wed, 1 Apr 2020 11:14:31 +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="PoHibI/M" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7EE31206E9 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]:58064 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJbKI-0006BL-Lv for qemu-devel@archiver.kernel.org; Wed, 01 Apr 2020 07:14:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60178) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jJbJF-0005Gf-7G for qemu-devel@nongnu.org; Wed, 01 Apr 2020 07:13:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jJbJD-00007x-M3 for qemu-devel@nongnu.org; Wed, 01 Apr 2020 07:13:24 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:60943 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jJbJD-00007G-CJ for qemu-devel@nongnu.org; Wed, 01 Apr 2020 07:13:23 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585739602; 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=Ez95WzjdwCLqrjXyuHkHO3HL1ZExDT6b4tUuMMLb/3I=; b=PoHibI/Mj62qOyQDA3Ft0TnBbBK2nnB7yfwDp7OL0Xs/CXtywi+GlivAkA3Xp3W49QrFm6 aS25AhqBxRtXPRlzs2VUibJkwoNFXig2w5/djVhTA4W9YIuf2v8dhqXH+IU7I05/FZEIJ+ wRgtvqMOtJzBdXTsaGxoQd0Ut+wrgSM= 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-194-_As59BF8O1i9Ne79cyNDBw-1; Wed, 01 Apr 2020 07:13:20 -0400 X-MC-Unique: _As59BF8O1i9Ne79cyNDBw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A3F99800D4E; Wed, 1 Apr 2020 11:13:19 +0000 (UTC) Received: from gondolin (ovpn-112-252.ams2.redhat.com [10.36.112.252]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5C8BC60BE2; Wed, 1 Apr 2020 11:13:14 +0000 (UTC) Date: Wed, 1 Apr 2020 13:12:43 +0200 From: Cornelia Huck To: Christian Borntraeger Subject: Re: [PATCH v2] vl/s390: fixup ram sizes for compat machines Message-ID: <20200401131243.14125f37.cohuck@redhat.com> In-Reply-To: <9f64cfb4-df6d-f43e-034c-f4e18a372e06@de.ibm.com> References: <20200401085014.100125-1-borntraeger@de.ibm.com> <20200401121324.379cfd0d.cohuck@redhat.com> <9f64cfb4-df6d-f43e-034c-f4e18a372e06@de.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.61 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: =?UTF-8?B?THVr?= =?UTF-8?B?w6HFoQ==?= Doktor , Thomas Huth , Janosch Frank , David Hildenbrand , qemu-devel , "Dr . David Alan Gilbert" , Halil Pasic , qemu-s390x , Igor Mammedov , Richard Henderson Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 1 Apr 2020 13:01:43 +0200 Christian Borntraeger wrote: > On 01.04.20 12:13, Cornelia Huck wrote: > > On Wed, 1 Apr 2020 04:50:14 -0400 > > Christian Borntraeger wrote: > > > >> Older QEMU versions did fixup the ram size to match what can be reported > >> via sclp. We need to mimic this behaviour for machine types 4.2 and > >> older to not fail on inbound migration for memory sizes that do not fit. > >> Old machines with proper aligned memory sizes are not affected. > >> > >> Alignment table: > >> VM size (<=) | Alignment > >> -------------------------- > >> 1020M | 1M > >> 2040M | 2M > >> 4080M | 4M > >> 8160M | 8M > >> 16320M | 16M > >> 32640M | 32M > >> 65280M | 64M > >> 130560M | 128M > >> 261120M | 256M > >> 522240M | 512M > >> 1044480M | 1G > >> 2088960M | 2G > >> 4177920M | 4G > >> 8355840M | 8G > >> > >> Suggested action is to replace unaligned -m value with a suitable > > > > "to replace any unaligned -m value" ? > > > >> aligned one or to use a machine version >= 5.0 as future versions might > >> remove the compatibility handling. > > > > I'm confused by the second part of the sentence. Warning about possible > > future removal of the compat stuff is fine, but I don't understand the > > suggestion to use a machine type >= 5.0. If I create a new machine that > > does not need be migrated to an old QEMU, using the latest machine type > > always seems like the best idea, right? And for a migration target it's > > not like we can choose the version freely anyway. > > > My point was that - when you redefine your guest, which is disruptive anyway > you could also change the machine version to 5.0 and keep the strange memory > size. Ah, ok. That depends however on whether you still need compatibility, so it might not be advisable. What about: "...or to switch to a machine version >= 5.0 if migration to older machine types is not needed; future versions might remove the compatibility handling." ?