From patchwork Fri Jul 5 22:14:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 1128351 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 45gVLM5360z9sNw for ; Sat, 6 Jul 2019 08:45:47 +1000 (AEST) Received: from localhost ([::1]:56706 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hjWxd-0003vA-Nf for incoming@patchwork.ozlabs.org; Fri, 05 Jul 2019 18:45:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:55067) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hjWUr-0007u8-1T for qemu-devel@nongnu.org; Fri, 05 Jul 2019 18:16:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hjWUq-0003ay-0T for qemu-devel@nongnu.org; Fri, 05 Jul 2019 18:16:00 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59986) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hjWUp-0003aj-PX for qemu-devel@nongnu.org; Fri, 05 Jul 2019 18:15:59 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 215383082E06; Fri, 5 Jul 2019 22:15:59 +0000 (UTC) Received: from localhost (ovpn-116-30.gru2.redhat.com [10.97.116.30]) by smtp.corp.redhat.com (Postfix) with ESMTP id A6DF19D90A; Fri, 5 Jul 2019 22:15:58 +0000 (UTC) From: Eduardo Habkost To: Peter Maydell , Paolo Bonzini , qemu-devel@nongnu.org, Marcel Apfelbaum , Richard Henderson Date: Fri, 5 Jul 2019 19:14:42 -0300 Message-Id: <20190705221504.25166-21-ehabkost@redhat.com> In-Reply-To: <20190705221504.25166-1-ehabkost@redhat.com> References: <20190705221504.25166-1-ehabkost@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.46]); Fri, 05 Jul 2019 22:15:59 +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 v6 20/42] 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 cb5fdbcb1e..dd5c6e2334 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 4a626f535d..e6891c3a93 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)