From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yi Zhang Subject: Re: [PATCH V5 0/4] Fix kvm misconceives NVDIMM pages as reserved mmio Date: Wed, 19 Sep 2018 18:55:05 +0800 Message-ID: <20180919105505.GA43643@tiger-server> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, jglisse-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, yi.z.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, rkrcmar-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org To: kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, dave.jiang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, yu.c.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, pagupta-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, david-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, jack-AlSwsSmVLrQ@public.gmane.org, hch-jcswGhMUV9g@public.gmane.org Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: kvm.vger.kernel.org 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 >