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=-21.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, 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 E3C0AC433ED for ; Wed, 28 Apr 2021 16:32:15 +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 2B868613FF for ; Wed, 28 Apr 2021 16:32:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B868613FF 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]:35464 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lbn6j-0008HY-TG for qemu-devel@archiver.kernel.org; Wed, 28 Apr 2021 12:32:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53404) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lbn4K-00078c-QZ for qemu-devel@nongnu.org; Wed, 28 Apr 2021 12:29:44 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:32703) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lbn4H-0006Tp-PW for qemu-devel@nongnu.org; Wed, 28 Apr 2021 12:29:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1619627380; 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=Co/dMFKm0k4Bh5ngAGA6PebzSt63Cg+l8mYlMiLmNds=; b=GlmRKk3Pb5r7MoLm2HZtWygoEbyaLTD5FXWw5PTXsYoXWa3NvC4QttWHnRY1zg6iBbiQyh efcHbr7JErKK/gqJBk81X678Nd5CBhjm5pwXerzGD+h0ZdB1guJcD4fxZGzkxAW2tj37BV PLgDA/Ws7wKUh9ROQXFLi2iTw2WJny0= 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-288-ZdhyTsCXNkaxII5kekdtxQ-1; Wed, 28 Apr 2021 12:29:38 -0400 X-MC-Unique: ZdhyTsCXNkaxII5kekdtxQ-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 75A28107ACE4 for ; Wed, 28 Apr 2021 16:29:37 +0000 (UTC) Received: from localhost (unknown [10.22.9.192]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9300C60CC9; Wed, 28 Apr 2021 16:29:30 +0000 (UTC) Date: Wed, 28 Apr 2021 12:29:30 -0400 From: Eduardo Habkost To: Igor Mammedov Subject: Re: [PATCH] Deprecate pmem=on with non-DAX capable backend file Message-ID: <20210428162929.bgwyol24brh2avfa@habkost.net> References: <20210111203332.740815-1-imammedo@redhat.com> <20210427204848.ubgncujxjxcufpul@habkost.net> MIME-Version: 1.0 In-Reply-To: <20210427204848.ubgncujxjxcufpul@habkost.net> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=ehabkost@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=ehabkost@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.22, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: thuth@redhat.com, "Michael S. Tsirkin" , libvir-list@redhat.com, qemu-devel@nongnu.org, pbonzini@redhat.com, philmd@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, Apr 27, 2021 at 04:48:48PM -0400, Eduardo Habkost wrote: > On Mon, Jan 11, 2021 at 03:33:32PM -0500, Igor Mammedov wrote: > > It is not safe to pretend that emulated NVDIMM supports > > persistence while backend actually failed to enable it > > and used non-persistent mapping as fall back. > > Instead of falling-back, QEMU should be more strict and > > error out with clear message that it's not supported. > > So if user asks for persistence (pmem=on), they should > > store backing file on NVDIMM. > > > > Signed-off-by: Igor Mammedov > > Reviewed-by: Philippe Mathieu-Daudé > > I'm queueing this for 6.1, after changing "since 6.0" to "since 6.1". > > Sorry for letting it fall through the cracks. This caused build failures[1] and I had to apply the following fixup. [1] https://gitlab.com/ehabkost/qemu/-/jobs/1216917482#L3444 Signed-off-by: Eduardo Habkost --- docs/system/deprecated.rst | 1 + 1 file changed, 1 insertion(+) diff --git a/docs/system/deprecated.rst b/docs/system/deprecated.rst index cc8d810be1a..c55c4bceb00 100644 --- a/docs/system/deprecated.rst +++ b/docs/system/deprecated.rst @@ -257,6 +257,7 @@ is (a) not DAX capable or (b) not on a filesystem that support direct mapping of persistent memory, is not safe and may lead to data loss or corruption in case of host crash. Options are: + - modify VM configuration to set ``pmem=off`` to continue using fake NVDIMM (without persistence guaranties) with backing file on non DAX storage - move backing file to NVDIMM storage and keep ``pmem=on`` -- 2.30.2 -- Eduardo