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=-0.3 required=3.0 tests=DATE_IN_FUTURE_03_06, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT 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 86135C433F5 for ; Fri, 7 Sep 2018 09:25:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 38054206BB for ; Fri, 7 Sep 2018 09:25:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 38054206BB 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 S1728413AbeIGOFJ (ORCPT ); Fri, 7 Sep 2018 10:05:09 -0400 Received: from mga14.intel.com ([192.55.52.115]:32754 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728317AbeIGOFI (ORCPT ); Fri, 7 Sep 2018 10:05:08 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Sep 2018 02:25:05 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,341,1531810800"; d="scan'208";a="81637128" Received: from linux.intel.com ([10.54.29.200]) by orsmga003.jf.intel.com with ESMTP; 07 Sep 2018 02:25:04 -0700 Received: from dazhang1-ssd.sh.intel.com (unknown [10.239.48.163]) by linux.intel.com (Postfix) with ESMTP id 5C75C5803DA; Fri, 7 Sep 2018 02:25:02 -0700 (PDT) From: Zhang Yi To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, pbonzini@redhat.com, dan.j.williams@intel.com, dave.jiang@intel.com, yu.c.zhang@intel.com, pagupta@redhat.com, david@redhat.com, jack@suse.cz, hch@lst.de Cc: linux-mm@kvack.org, rkrcmar@redhat.com, jglisse@redhat.com, yi.z.zhang@intel.com, Zhang Yi Subject: [PATCH V5 4/4] kvm: add a check if pfn is from NVDIMM pmem. Date: Sat, 8 Sep 2018 02:04:08 +0800 Message-Id: <4e8c2e0facd46cfaf4ab79e19c9115958ab6f218.1536342881.git.yi.z.zhang@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 identify 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. Signed-off-by: Zhang Yi Acked-by: Pankaj Gupta --- virt/kvm/kvm_main.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index c44c406..9c49634 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -147,8 +147,20 @@ __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); + + /* + * For device specific memory space, there is a case + * which we need pass MEMORY_DEVICE_FS[DEV]_DAX pages + * to kvm, these pages marked reserved flag as it is a + * zone device memory, we need to identify these pages + * and let kvm treat these as normal pages + */ + return PageReserved(page) && !is_dax_page(page); + } return true; } -- 2.7.4