From patchwork Wed Jul 3 21:07:59 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 1127195 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 ozlabs.org (Postfix) with ESMTPS id 45fDkW0vFbz9s4V for ; Thu, 4 Jul 2019 07:28:51 +1000 (AEST) Received: from localhost ([::1]:40802 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1himo5-0000pg-6j for incoming@patchwork.ozlabs.org; Wed, 03 Jul 2019 17:28:49 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38171) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1himVI-00068H-G0 for qemu-devel@nongnu.org; Wed, 03 Jul 2019 17:09:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1himVG-0006zf-Qw for qemu-devel@nongnu.org; Wed, 03 Jul 2019 17:09:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55712) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1himVG-0006x5-4r for qemu-devel@nongnu.org; Wed, 03 Jul 2019 17:09:22 -0400 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F3179308222F; Wed, 3 Jul 2019 21:09:18 +0000 (UTC) Received: from localhost (ovpn-116-30.gru2.redhat.com [10.97.116.30]) by smtp.corp.redhat.com (Postfix) with ESMTP id 86AB81001925; Wed, 3 Jul 2019 21:09:18 +0000 (UTC) From: Eduardo Habkost To: Peter Maydell , Paolo Bonzini , qemu-devel@nongnu.org, Marcel Apfelbaum , Richard Henderson Date: Wed, 3 Jul 2019 18:07:59 -0300 Message-Id: <20190703210821.27550-22-ehabkost@redhat.com> In-Reply-To: <20190703210821.27550-1-ehabkost@redhat.com> References: <20190703210821.27550-1-ehabkost@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Wed, 03 Jul 2019 21:09:19 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL v5 21/43] deprecate -mem-path fallback to anonymous RAM 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: Igor Mammedov Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Igor Mammedov Fallback might affect guest or worse whole host performance or functionality if backing file were used to share guest RAM with another process. Patch deprecates fallback so that we could remove it in future and ensure that QEMU will provide expected behavior and fail if it can't use user provided backing file. Signed-off-by: Igor Mammedov Reviewed-by: Daniel P. Berrangé Reviewed-by: Markus Armbruster Message-Id: <20190626074228.11558-1-imammedo@redhat.com> Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Eduardo Habkost --- hw/core/numa.c | 6 ++++-- qemu-deprecated.texi | 9 +++++++++ 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/hw/core/numa.c b/hw/core/numa.c index b74262b743..7faec75a07 100644 --- a/hw/core/numa.c +++ b/hw/core/numa.c @@ -479,8 +479,10 @@ static void allocate_system_memory_nonnuma(MemoryRegion *mr, Object *owner, if (mem_prealloc) { exit(1); } - error_report("falling back to regular RAM allocation."); - + warn_report("falling back to regular RAM allocation"); + error_printf("This is deprecated. Make sure that -mem-path " + " specified path has sufficient resources to allocate" + " -m specified RAM amount"); /* Legacy behavior: if allocation failed, fall back to * regular RAM allocation. */ diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi index 2fe9b72121..9cba82d5ec 100644 --- a/qemu-deprecated.texi +++ b/qemu-deprecated.texi @@ -112,6 +112,15 @@ QEMU using implicit generic or board specific splitting rule. Use @option{memdev} with @var{memory-backend-ram} backend or @option{mem} (if it's supported by used machine type) to define mapping explictly instead. +@subsection -mem-path fallback to RAM (since 4.1) +Currently if guest RAM allocation from file pointed by @option{mem-path} +fails, QEMU falls back to allocating from RAM, which might result +in unpredictable behavior since the backing file specified by the user +is ignored. In the future, users will be responsible for making sure +the backing storage specified with @option{-mem-path} can actually provide +the guest RAM configured with @option{-m} and QEMU will fail to start up if +RAM allocation is unsuccessful. + @section QEMU Machine Protocol (QMP) commands @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)