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 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 B3E89C46464 for ; Mon, 13 Aug 2018 09:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 609C52172E for ; Mon, 13 Aug 2018 09:53:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 609C52172E 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 S1729010AbeHMMez (ORCPT ); Mon, 13 Aug 2018 08:34:55 -0400 Received: from mga03.intel.com ([134.134.136.65]:53057 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728310AbeHMMez (ORCPT ); Mon, 13 Aug 2018 08:34:55 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Aug 2018 02:48:22 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,232,1531810800"; d="scan'208";a="253629167" Received: from dazhang1-z97x.sh.intel.com (HELO [10.239.13.128]) ([10.239.13.128]) by fmsmga005.fm.intel.com with ESMTP; 13 Aug 2018 02:48:01 -0700 Subject: Re: [PATCH V3 4/4] kvm: add a check if pfn is from NVDIMM pmem. To: Pankaj Gupta Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, pbonzini@redhat.com, dan j williams , jack@suse.cz, hch@lst.de, yu c zhang , linux-mm@kvack.org, rkrcmar@redhat.com, yi z zhang References: <0cc6cba7020f80168695fba731b8fd72fd649dc8.1533811181.git.yi.z.zhang@linux.intel.com> <2130082365.883434.1533803526182.JavaMail.zimbra@redhat.com> From: "Zhang,Yi" Message-ID: <083b8170-a9ba-beee-7578-6d33e70a8b6e@linux.intel.com> Date: Tue, 14 Aug 2018 01:32:05 +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: <2130082365.883434.1533803526182.JavaMail.zimbra@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 On 2018年08月09日 16:32, Pankaj Gupta 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 > s/indentify/identify & remove '.' Thanks Pankaj, :-) > >> 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 >> >> Signed-off-by: Zhang Yi >> --- >> virt/kvm/kvm_main.c | 8 ++++++-- >> 1 file changed, 6 insertions(+), 2 deletions(-) >> >> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c >> index c44c406..969b6ca 100644 >> --- a/virt/kvm/kvm_main.c >> +++ b/virt/kvm/kvm_main.c >> @@ -147,8 +147,12 @@ __weak void >> kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm, >> >> bool kvm_is_reserved_pfn(kvm_pfn_t pfn) >> { >> - if (pfn_valid(pfn)) >> - return PageReserved(pfn_to_page(pfn)); >> + struct page *page; >> + >> + if (pfn_valid(pfn)) { >> + page = pfn_to_page(pfn); >> + return PageReserved(page) && !is_dax_page(page); >> + } >> >> return true; >> } >> -- >> 2.7.4 >> >>