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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 6F477C35656 for ; Fri, 21 Feb 2020 15:38:19 +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 47700206E2 for ; Fri, 21 Feb 2020 15:38:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 47700206E2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59960 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j5ANd-0000Kb-8N for qemu-devel@archiver.kernel.org; Fri, 21 Feb 2020 10:38:17 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:38196) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j5AMM-0007YH-Oy for qemu-devel@nongnu.org; Fri, 21 Feb 2020 10:36:59 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j5AML-0002RS-JB for qemu-devel@nongnu.org; Fri, 21 Feb 2020 10:36:58 -0500 Received: from mga01.intel.com ([192.55.52.88]:3589) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j5AML-000249-7H; Fri, 21 Feb 2020 10:36:57 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 21 Feb 2020 07:36:51 -0800 X-IronPort-AV: E=Sophos;i="5.70,468,1574150400"; d="scan'208";a="225246469" Received: from ajakowsk-mobl1.amr.corp.intel.com (HELO localhost.localdomain) ([10.78.27.169]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 21 Feb 2020 07:36:50 -0800 Subject: Re: [PATCH v1] block/nvme: introduce PMR support from NVMe 1.4 spec To: Stefan Hajnoczi References: <20200218224811.30050-1-andrzej.jakowski@linux.intel.com> <20200221134555.GK1484511@stefanha-x1.localdomain> From: Andrzej Jakowski Message-ID: Date: Fri, 21 Feb 2020 08:36:50 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20200221134555.GK1484511@stefanha-x1.localdomain> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 192.55.52.88 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: kwolf@redhat.com, Haozhong Zhang , qemu-block@nongnu.org, qemu-devel@nongnu.org, mreitz@redhat.com, keith.busch@intel.com, Zhang Yi , Junyan He , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2/21/20 6:45 AM, Stefan Hajnoczi wrote: > Why is msync(2) done on memory loads instead of stores? This is my interpretation of NVMe spec wording with regards to PMRWBM field which says: "The completion of a memory read from any Persistent Memory Region address ensures that all prior writes to the Persistent Memory Region have completed and are persistent."