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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 6684BC43331 for ; Tue, 24 Mar 2020 19:01:08 +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 30E5B2076F for ; Tue, 24 Mar 2020 19:01:08 +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="MHjexZuR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 30E5B2076F 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]:53754 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jGonT-0004cM-74 for qemu-devel@archiver.kernel.org; Tue, 24 Mar 2020 15:01:07 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44559) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jGomV-00041x-Er for qemu-devel@nongnu.org; Tue, 24 Mar 2020 15:00:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jGomU-0000Ld-6r for qemu-devel@nongnu.org; Tue, 24 Mar 2020 15:00:07 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:50083) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jGomU-0000LK-16 for qemu-devel@nongnu.org; Tue, 24 Mar 2020 15:00:06 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585076405; 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=tJ13Rwd9X4lovMwvDdoTXYBJ8H25eDYm551Mp+4LLGU=; b=MHjexZuRRmgCG7gDfucP6HjXH37mWlm5pPtL4oe1uKHlQjc2CH0Gsw2Qp5Y2SNrGFKNEOf 3KDHZDANwPnyFEAYJZWy4rYS63OyGeT0vmzJvge92zq2qdzI0Xhn7OydQDAvw1TKkUTKE3 SNz6GHnsfzr24U7xhDAsDugEzlhawTw= 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-373-8kTvVdYbO6WdqqoEDK_pAw-1; Tue, 24 Mar 2020 15:00:04 -0400 X-MC-Unique: 8kTvVdYbO6WdqqoEDK_pAw-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 1402B189D6C3 for ; Tue, 24 Mar 2020 19:00:03 +0000 (UTC) Received: from work-vm (ovpn-114-253.ams2.redhat.com [10.36.114.253]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 283365DA7C; Tue, 24 Mar 2020 18:59:58 +0000 (UTC) Date: Tue, 24 Mar 2020 18:59:56 +0000 From: "Dr. David Alan Gilbert" To: Igor Mammedov Subject: Re: [PATCH for-5.0] vl.c: fix migration failure for 3.1 and older machine types Message-ID: <20200324185956.GF17043@work-vm> References: <20200304172748.15338-1-imammedo@redhat.com> <20200317175213.217c3969@office.mammed.net> MIME-Version: 1.0 In-Reply-To: <20200317175213.217c3969@office.mammed.net> User-Agent: Mutt/1.13.3 (2020-01-12) 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 Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 216.205.24.74 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, qemu-devel@nongnu.org, marcandre.lureau@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Igor Mammedov (imammedo@redhat.com) wrote: > On Wed, 4 Mar 2020 12:27:48 -0500 > Igor Mammedov wrote: >=20 > > 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 mi= gration > > qemu-system-ppc64: error while loading state for instance 0x0 of devi= ce '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 >=20 >=20 > ping, >=20 > so we don't forget to merge it I'm queueing this. > > --- > > 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 *m= s, const char *path) > > object_property_set_int(obj, ms->ram_size, "size", &error_fatal); > > object_property_add_child(object_get_objects_root(), mc->default_r= am_id, > > obj, &error_fatal); > > + /* Ensure backend's memory region name is equal to mc->default_ram= _id */ > > + object_property_set_bool(obj, false, "x-use-canonical-path-for-ram= block-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-ba= ckend", >=20 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK