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=-6.8 required=3.0 tests=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 70612C4646B for ; Wed, 26 Jun 2019 07:43:26 +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 483A82086D for ; Wed, 26 Jun 2019 07:43:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 483A82086D 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]:37312 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hg2aT-00052O-71 for qemu-devel@archiver.kernel.org; Wed, 26 Jun 2019 03:43:25 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34933) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hg2Zm-0004bU-P7 for qemu-devel@nongnu.org; Wed, 26 Jun 2019 03:42:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hg2Zl-0007mP-EL for qemu-devel@nongnu.org; Wed, 26 Jun 2019 03:42:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39742) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hg2Zl-0007ks-8L for qemu-devel@nongnu.org; Wed, 26 Jun 2019 03:42:41 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B129E3082263 for ; Wed, 26 Jun 2019 07:42:34 +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 8FBFB5D717; Wed, 26 Jun 2019 07:42:33 +0000 (UTC) From: Igor Mammedov To: qemu-devel@nongnu.org Date: Wed, 26 Jun 2019 03:42:28 -0400 Message-Id: <20190626074228.11558-1-imammedo@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.45]); Wed, 26 Jun 2019 07:42:34 +0000 (UTC) Content-Transfer-Encoding: quoted-printable 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] [PATCH v3] 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: berrange@redhat.com, ehabkost@redhat.com, dgilbert@redhat.com, armbru@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" 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. Berrang=C3=A9 Reviewed-by: Markus Armbruster --- v2: * improve text language (Markus Armbruster ) v3: * drop confusing 'or QEMU will fail to start' in error message * fix up grammar error (Markus Armbruster ) numa.c | 6 ++++-- qemu-deprecated.texi | 9 +++++++++ 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/numa.c b/numa.c index 91a29138a2..1994ab0655 100644 --- a/numa.c +++ b/numa.c @@ -494,8 +494,10 @@ static void allocate_system_memory_nonnuma(MemoryReg= ion *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 al= locate" + " -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 splitt= ing 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= . =20 +@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 provi= de +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 =20 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0) --=20 2.18.1