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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 B3863C10F29 for ; Tue, 17 Mar 2020 16:54:40 +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 81C962073E for ; Tue, 17 Mar 2020 16:54:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UgTDTWpf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81C962073E 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]:36930 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEFUF-00060F-Il for qemu-devel@archiver.kernel.org; Tue, 17 Mar 2020 12:54:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55505) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jEFS4-0002Rh-7V for qemu-devel@nongnu.org; Tue, 17 Mar 2020 12:52:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jEFS2-0003el-TI for qemu-devel@nongnu.org; Tue, 17 Mar 2020 12:52:24 -0400 Received: from us-smtp-delivery-74.mimecast.com ([63.128.21.74]:20005) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jEFS2-0003aH-NO for qemu-devel@nongnu.org; Tue, 17 Mar 2020 12:52:22 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1584463942; 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=kx8+EOhssb9Itsb352KEYDK/Yxdu2Z9JmwOVUEoxxsE=; b=UgTDTWpfGTjW4VQ+tNYSBvCrcnBd2sG+JYrMj1+dHL9aJvzjGJQga6Ob57mXWyK9O6mRNH +cW3bDy7GIx/EE1ERFDKuJd1CRT1M5GWI3yd4t2mlYYr8nf0BsZuFUC1rdXEbxDzbG+gFW knUbcvZN2KNWaJnj70YyHHiSPIzURv8= 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-320-Il12puKxMO2GMJJIoGWc2Q-1; Tue, 17 Mar 2020 12:52:20 -0400 X-MC-Unique: Il12puKxMO2GMJJIoGWc2Q-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 890CE108443B for ; Tue, 17 Mar 2020 16:52:19 +0000 (UTC) Received: from office.mammed.net (unknown [10.40.195.235]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6CE825D9E5; Tue, 17 Mar 2020 16:52:15 +0000 (UTC) Date: Tue, 17 Mar 2020 17:52:13 +0100 From: Igor Mammedov To: qemu-devel@nongnu.org Subject: Re: [PATCH for-5.0] vl.c: fix migration failure for 3.1 and older machine types Message-ID: <20200317175213.217c3969@office.mammed.net> In-Reply-To: <20200304172748.15338-1-imammedo@redhat.com> References: <20200304172748.15338-1-imammedo@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 63.128.21.74 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: ldoktor@redhat.com, pbonzini@redhat.com, dgilbert@redhat.com, marcandre.lureau@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 4 Mar 2020 12:27:48 -0500 Igor Mammedov wrote: > Migration from QEMU(v4.0) fails when using 3.1 or older machine > type. For example if one attempts to migrate > QEMU-2.12 started as > qemu-system-ppc64 -nodefaults -M pseries-2.12 -m 4096 -mem-path /tmp/ > to current master, it will fail with > qemu-system-ppc64: Unknown ramblock "ppc_spapr.ram", cannot accept migr= ation > qemu-system-ppc64: error while loading state for instance 0x0 of device= 'ram' > qemu-system-ppc64: load of migration failed: Invalid argument >=20 > Caused by 900c0ba373 commit which switches main RAM allocation to > memory backends and the fact in 3.1 and older QEMU, backends used > full[***] QOM path as memory region name instead of backend's name. > That was changed after 3.1 to use prefix-less names by default > (fa0cb34d22) for new machine types. > *** effectively makes main RAM memory region names defined by > MachineClass::default_ram_id being altered with '/objects/' prefix > and therefore migration fails as old QEMU sends prefix-less > name while new QEMU expects name with prefix when using 3.1 and > older machine types. >=20 > Fix it by forcing implicit[1] memory backend to always use > prefix-less names for its memory region by setting > 'x-use-canonical-path-for-ramblock-id' > property to false. >=20 > 1) i.e. memory backend created by compat glue which maps > -m/-mem-path/-mem-prealloc/default RAM size into > appropriate backend type/options to match old CLI format. >=20 > Fixes: 900c0ba373 > Signed-off-by: Igor Mammedov > Reported-by: Luk=C3=A1=C5=A1 Doktor ping, so we don't forget to merge it > --- > CC: ldoktor@redhat.com > CC: marcandre.lureau@redhat.com > CC: dgilbert@redhat.com > --- > softmmu/vl.c | 3 +++ > 1 file changed, 3 insertions(+) >=20 > diff --git a/softmmu/vl.c b/softmmu/vl.c > index 5549f4b619..1101b1cb41 100644 > --- a/softmmu/vl.c > +++ b/softmmu/vl.c > @@ -2800,6 +2800,9 @@ static void create_default_memdev(MachineState *ms,= const char *path) > object_property_set_int(obj, ms->ram_size, "size", &error_fatal); > object_property_add_child(object_get_objects_root(), mc->default_ram= _id, > obj, &error_fatal); > + /* Ensure backend's memory region name is equal to mc->default_ram_i= d */ > + object_property_set_bool(obj, false, "x-use-canonical-path-for-rambl= ock-id", > + &error_fatal); > user_creatable_complete(USER_CREATABLE(obj), &error_fatal); > object_unref(obj); > object_property_set_str(OBJECT(ms), mc->default_ram_id, "memory-back= end",