From nobody Mon Feb 9 20:46:20 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=intel.com ARC-Seal: i=1; a=rsa-sha256; t=1586922143; cv=none; d=zohomail.com; s=zohoarc; b=IiuDhTZ/Z9NK48FpP0akg5k9uZnl7lZ1nak9CE2oDuMZQ0cNVSopUm4RbWanutfihZgrRX+QcU0xecLWL+kh2Ivo0oOiDE9wppe+r5Rb2byaZDe1Ds2RG+OpW+A+8ub+366DkqFXPmMmh/J/WSjp/4Va7tistYCZq+mlHaIzMmg= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1586922143; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=HeOa1vBW74nbASGIi9ALu9HUaJFozr4TlkRE7pPHLd8=; b=Uz0hXjsq5Pgy5mPfpSRsKl29E2OTmnaNwlXL0cO6huMbSkKN03pEkRDi094QJfFzdUlSzei6dVTIV8ccL0WnbSs/vrsiydcuMv86ZDnaQDLpMAnFM709shV+BgrpSC36BpdGZ7ARDtQxflMxTRGtrhAwSpMqZk5Px0i5K2ozAUw= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1586922143009997.9865890215841; Tue, 14 Apr 2020 20:42:23 -0700 (PDT) Received: from localhost ([::1]:42370 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jOYwP-0005H3-NI for importer@patchew.org; Tue, 14 Apr 2020 23:42:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48654) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jOYuW-000295-1p for qemu-devel@nongnu.org; Tue, 14 Apr 2020 23:40:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jOYuU-0000kj-G0 for qemu-devel@nongnu.org; Tue, 14 Apr 2020 23:40:23 -0400 Received: from mga01.intel.com ([192.55.52.88]:4323) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jOYuU-0000jA-0X for qemu-devel@nongnu.org; Tue, 14 Apr 2020 23:40:22 -0400 Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2020 20:40:17 -0700 Received: from dazhang1-mobile.sh.intel.com ([10.239.48.70]) by orsmga006.jf.intel.com with ESMTP; 14 Apr 2020 20:40:15 -0700 IronPort-SDR: VJhoo/Om8EEMi09m5tPil2QmzCj2Su/N4SrlkJnER8OzsECB3iInjD8slfWWX5KFS+lKUo1AQI t3KUDeD9RtTQ== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False IronPort-SDR: stj/CEM85xbeawe0j05JhvWneRlBBntwJhlPCiM/DboGrfuPlM92I5bx6LcL1KGpwKZ9rIFJt0 dLTdzhtsSxDQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,385,1580803200"; d="scan'208";a="256729963" From: Jingqi Liu To: Paolo Bonzini , Richard Henderson , Xiao Guangrong , Dan Williams Subject: [PATCH v2 2/3] docs/nvdimm: add description of alignment requirement of device dax Date: Wed, 15 Apr 2020 11:35:37 +0800 Message-Id: <20200415033538.43329-3-jingqi.liu@intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200415033538.43329-1-jingqi.liu@intel.com> References: <20200415033538.43329-1-jingqi.liu@intel.com> X-detected-operating-system: by eggs.gnu.org: FreeBSD 9.x [fuzzy] 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: Jingqi Liu , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" For device dax (e.g., /dev/dax0.0), the NUM of 'align=3DNUM' option needs to match the alignment requirement of the device dax. It must be larger than or equal to the 'align' of device dax. Signed-off-by: Jingqi Liu --- docs/nvdimm.txt | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/docs/nvdimm.txt b/docs/nvdimm.txt index 362e99109e..3c7b6dab5f 100644 --- a/docs/nvdimm.txt +++ b/docs/nvdimm.txt @@ -132,6 +132,15 @@ address to the page size (getpagesize(2)) by default. = However, some types of backends may require an alignment different than the page size. In that case, QEMU v2.12.0 and later provide 'align' option to memory-backend-file to allow users to specify the proper alignment. +For device dax (e.g., /dev/dax0.0), this alignment needs to match the +alignment requirement of the device dax. The NUM of 'align=3DNUM' option +must be larger than or equal to the 'align' of device dax. +We can use the following command to show the 'align' of device dax. + + ndctl list -X + +In order to get the proper 'align' of device dax, you need to install +the library 'libdaxctl'. =20 For example, device dax require the 2 MB alignment, so we can use following QEMU command line options to use it (/dev/dax0.0) as the --=20 2.17.1