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=-0.8 required=3.0 tests=DATE_IN_FUTURE_06_12, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 85B84ECDFB8 for ; Fri, 20 Jul 2018 08:38:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3B7FC20673 for ; Fri, 20 Jul 2018 08:38:57 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B7FC20673 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 S1728384AbeGTJ0G (ORCPT ); Fri, 20 Jul 2018 05:26:06 -0400 Received: from mga02.intel.com ([134.134.136.20]:32574 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727347AbeGTJ0G (ORCPT ); Fri, 20 Jul 2018 05:26:06 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jul 2018 01:38:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,378,1526367600"; d="scan'208";a="76370846" Received: from dazhang1-z97x.sh.intel.com (HELO [10.239.13.115]) ([10.239.13.115]) by orsmga002.jf.intel.com with ESMTP; 20 Jul 2018 01:38:44 -0700 Subject: Re: [PATCH V2 0/4] Fix kvm misconceives NVDIMM pages as reserved mmio To: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, dan.j.williams@intel.com, jack@suse.cz, hch@lst.de, yu.c.zhang@intel.com, dave.jiang@intel.com Cc: linux-mm@kvack.org, rkrcmar@redhat.com, yi.z.zhang@intel.com References: <25569674-2d8f-8b54-4ba7-478b57067325@redhat.com> From: "Zhang,Yi" Message-ID: <3e822509-dc66-0fe8-bad6-d4e4ef9eb528@linux.intel.com> Date: Sat, 21 Jul 2018 00:24:41 +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: <25569674-2d8f-8b54-4ba7-478b57067325@redhat.com> 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 Thanks Paolo, let's wait Jan&Dan 's comments. Thank you, Paolo. Regards Yi On 2018年07月20日 16:32, Paolo Bonzini wrote: > On 20/07/2018 16:11, Zhang,Yi wrote: >> Added Jiang,Dave, >> >> Ping for further review, comments. > I need an Acked-by from the MM people to merge this. Jan, Dan? > > Paolo > >> Thanks All >> >> Regards >> Yi. >> >> >> On 2018年07月11日 01:01, Zhang Yi wrote: >>> For device specific memory space, when we move these area of pfn to >>> memory zone, we will set the page reserved flag at that time, some of >>> these reserved for device mmio, and some of these are not, such as >>> NVDIMM pmem. >>> >>> Now, we map these dev_dax or fs_dax pages to kvm for DIMM/NVDIMM >>> backend, since these pages are reserved. the check of >>> kvm_is_reserved_pfn() misconceives those pages as MMIO. Therefor, we >>> introduce 2 page map types, MEMORY_DEVICE_FS_DAX/MEMORY_DEVICE_DEV_DAX, >>> to indentify these pages are from NVDIMM pmem. and let kvm treat these >>> as normal pages. >>> >>> Without this patch, Many operations will be missed due to this >>> mistreatment to pmem pages. For example, a page may not have chance to >>> be unpinned for KVM guest(in kvm_release_pfn_clean); not able to be >>> marked as dirty/accessed(in kvm_set_pfn_dirty/accessed) etc. >>> >>> V1: >>> https://lkml.org/lkml/2018/7/4/91 >>> >>> V2: >>> *Add documentation for MEMORY_DEVICE_DEV_DAX memory type in comment block >>> *Add is_dax_page() in mm.h to differentiate the pages is from DAX device. >>> *Remove the function kvm_is_nd_pfn(). >>> >>> Zhang Yi (4): >>> kvm: remove redundant reserved page check >>> mm: introduce memory type MEMORY_DEVICE_DEV_DAX >>> mm: add a function to differentiate the pages is from DAX device >>> memory >>> kvm: add a check if pfn is from NVDIMM pmem. >>> >>> drivers/dax/pmem.c | 1 + >>> include/linux/memremap.h | 9 +++++++++ >>> include/linux/mm.h | 12 ++++++++++++ >>> virt/kvm/kvm_main.c | 16 ++++++++-------- >>> 4 files changed, 30 insertions(+), 8 deletions(-) >>> >>