From patchwork Wed Mar 4 17:27:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Igor Mammedov X-Patchwork-Id: 11420515 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5DC36921 for ; Wed, 4 Mar 2020 17:28:33 +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 34126217F4 for ; Wed, 4 Mar 2020 17:28:33 +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="CbpYE/aO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 34126217F4 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:37418 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j9Xou-0003BA-6M for patchwork-qemu-devel@patchwork.kernel.org; Wed, 04 Mar 2020 12:28:32 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:43968) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j9XoP-0002je-Av for qemu-devel@nongnu.org; Wed, 04 Mar 2020 12:28:02 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j9XoN-0007Sl-Tt for qemu-devel@nongnu.org; Wed, 04 Mar 2020 12:28:00 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:54458 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j9XoN-0007RH-N4 for qemu-devel@nongnu.org; Wed, 04 Mar 2020 12:27:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1583342878; 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; bh=fACmvQmkZuNIoscJtCfOcHGzOFDNYo96ZxSk+GGoTTs=; b=CbpYE/aOYojZjV0ZeIeImBtwExTFbFbHU47/b0CSXA7EtIgwP5quCsvobbFKYqGAKSHrGS M9RksZR1I+t20MPljAm5wKKI4r2E8L+yEsmMP8jnWJkKXhpduc1pzsYYNo1uSRz6AxLQxq aCOHRA2lgheaf4ixEPnm1EZyFfs06VA= 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-438-l8g6CjPvOoesDK64QA0UaA-1; Wed, 04 Mar 2020 12:27:56 -0500 X-MC-Unique: l8g6CjPvOoesDK64QA0UaA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CD90513FE for ; Wed, 4 Mar 2020 17:27:55 +0000 (UTC) Received: from dell-r430-03.lab.eng.brq.redhat.com (dell-r430-03.lab.eng.brq.redhat.com [10.37.153.18]) by smtp.corp.redhat.com (Postfix) with ESMTP id B9A2848; Wed, 4 Mar 2020 17:27:51 +0000 (UTC) From: Igor Mammedov To: qemu-devel@nongnu.org Subject: [PATCH for-5.0] vl.c: fix migration failure for 3.1 and older machine types Date: Wed, 4 Mar 2020 12:27:48 -0500 Message-Id: <20200304172748.15338-1-imammedo@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" 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 migration qemu-system-ppc64: error while loading state for instance 0x0 of device 'ram' qemu-system-ppc64: load of migration failed: Invalid argument 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. 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. 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. Fixes: 900c0ba373 Signed-off-by: Igor Mammedov Reported-by: Lukáš Doktor Tested-by: Lukáš Doktor Reviewed-by: Marc-André Lureau --- CC: ldoktor@redhat.com CC: marcandre.lureau@redhat.com CC: dgilbert@redhat.com --- softmmu/vl.c | 3 +++ 1 file changed, 3 insertions(+) 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_id */ + object_property_set_bool(obj, false, "x-use-canonical-path-for-ramblock-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-backend",