From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f200.google.com (mail-pl1-f200.google.com [209.85.214.200]) by kanga.kvack.org (Postfix) with ESMTP id 406FE8E0001 for ; Tue, 18 Sep 2018 22:16:05 -0400 (EDT) Received: by mail-pl1-f200.google.com with SMTP id d40-v6so1749015pla.14 for ; Tue, 18 Sep 2018 19:16:05 -0700 (PDT) Received: from mga06.intel.com (mga06.intel.com. [134.134.136.31]) by mx.google.com with ESMTPS id a190-v6si20300864pgc.241.2018.09.18.19.16.03 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Sep 2018 19:16:03 -0700 (PDT) Date: Wed, 19 Sep 2018 18:55:05 +0800 From: Yi Zhang Subject: Re: [PATCH V5 0/4] Fix kvm misconceives NVDIMM pages as reserved mmio Message-ID: <20180919105505.GA43643@tiger-server> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org List-ID: 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 Any comments? Hi Pankaj and Paolo, Can we Queue this to merge list since there no other comments last 2 weeks? Regards Yi. On 2018-09-08 at 02:03:02 +0800, 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: > https://lkml.org/lkml/2018/7/10/135 > > V3: > https://lkml.org/lkml/2018/8/9/17 > > V4: > https://lkml.org/lkml/2018/8/22/17 > > V5: > [PATCH V3 1/4] Reviewed-by: David / Acked-by: Pankaj > [PATCH V3 2/4] Reviewed-by: Jan > [PATCH V3 3/4] Acked-by: Jan > [PATCH V3 4/4] Added "Acked-by: Pankaj", Added in-line comments: Dave > > 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 | 8 ++++++++ > include/linux/mm.h | 12 ++++++++++++ > virt/kvm/kvm_main.c | 24 ++++++++++++++++-------- > 4 files changed, 37 insertions(+), 8 deletions(-) > > -- > 2.7.4 >