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=1.4 required=3.0 tests=DATE_IN_FUTURE_03_06, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 AF920C46470 for ; Wed, 8 Aug 2018 01:38:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4983621566 for ; Wed, 8 Aug 2018 01:38:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4983621566 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726975AbeHHDzt (ORCPT ); Tue, 7 Aug 2018 23:55:49 -0400 Received: from mga07.intel.com ([134.134.136.100]:46499 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726245AbeHHDzs (ORCPT ); Tue, 7 Aug 2018 23:55:48 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Aug 2018 18:38:38 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,456,1526367600"; d="scan'208";a="74635618" Received: from unknown (HELO [10.239.13.128]) ([10.239.13.128]) by fmsmga002.fm.intel.com with ESMTP; 07 Aug 2018 18:38:36 -0700 Subject: Re: [PATCH V2 2/4] mm: introduce memory type MEMORY_DEVICE_DEV_DAX To: Jan Kara Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, pbonzini@redhat.com, dan.j.williams@intel.com, hch@lst.de, yu.c.zhang@intel.com, linux-mm@kvack.org, rkrcmar@redhat.com, yi.z.zhang@intel.com References: <7e20d862f96662e1a7736dbb747a71949933dcd4.1531241281.git.yi.z.zhang@linux.intel.com> <20180807091120.ybne44o2fy2mxcch@quack2.suse.cz> From: "Zhang,Yi" Message-ID: <60a42f73-1772-24eb-26f0-efd892b0487c@linux.intel.com> Date: Wed, 8 Aug 2018 17:22:42 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20180807091120.ybne44o2fy2mxcch@quack2.suse.cz> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2018年08月07日 17:11, Jan Kara wrote: > On Wed 11-07-18 01:01:59, Zhang Yi wrote: >> Currently, NVDIMM pages will be marked 'PageReserved'. However, unlike >> other reserved PFNs, pages on NVDIMM shall still behave like normal ones >> in many cases, i.e. when used as backend memory of KVM guest. This patch >> introduces a new memory type, MEMORY_DEVICE_DEV_DAX. And set this flag >> while dax driver hotplug the device memory. >> >> Signed-off-by: Zhang Yi >> Signed-off-by: Zhang Yu >> --- >> drivers/dax/pmem.c | 1 + >> include/linux/memremap.h | 9 +++++++++ >> 2 files changed, 10 insertions(+) >> >> diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c >> index fd49b24..fb3f363 100644 >> --- a/drivers/dax/pmem.c >> +++ b/drivers/dax/pmem.c >> @@ -111,6 +111,7 @@ static int dax_pmem_probe(struct device *dev) >> return rc; >> >> dax_pmem->pgmap.ref = &dax_pmem->ref; >> + dax_pmem->pgmap.type = MEMORY_DEVICE_DEV_DAX; >> addr = devm_memremap_pages(dev, &dax_pmem->pgmap); >> if (IS_ERR(addr)) >> return PTR_ERR(addr); >> diff --git a/include/linux/memremap.h b/include/linux/memremap.h >> index 5ebfff6..a36bce8 100644 >> --- a/include/linux/memremap.h >> +++ b/include/linux/memremap.h >> @@ -53,11 +53,20 @@ struct vmem_altmap { >> * wakeup event whenever a page is unpinned and becomes idle. This >> * wakeup is used to coordinate physical address space management (ex: >> * fs truncate/hole punch) vs pinned pages (ex: device dma). >> + * >> + * MEMORY_DEVICE_DEV_DAX: >> + * DAX driver hotplug the device memory and move it to memory zone, these >> + * pages will be marked reserved flag. However, some other kernel componet >> + * will misconceive these pages are reserved mmio (ex: we map these dev_dax >> + * or fs_dax pages to kvm for DIMM/NVDIMM backend). Together with the type >> + * MEMORY_DEVICE_FS_DAX, we can differentiate the pages on NVDIMM with the >> + * normal reserved pages. > So I believe the description should be in terms of what kind of memory is > the MEMORY_DEVICE_DEV_DAX type, not how users use this type. See comments > for other memory types... > > Honza Yes, agree, thanks for your kindly review. Jan. > >> */ >> enum memory_type { >> MEMORY_DEVICE_PRIVATE = 1, >> MEMORY_DEVICE_PUBLIC, >> MEMORY_DEVICE_FS_DAX, >> + MEMORY_DEVICE_DEV_DAX, >> }; >> >> /* >> -- >> 2.7.4 >>