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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A2280C06510 for ; Tue, 2 Jul 2019 08:53:49 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 76FAE2089C for ; Tue, 2 Jul 2019 08:53:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 76FAE2089C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:50736 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hiEXs-0005ct-Po for qemu-devel@archiver.kernel.org; Tue, 02 Jul 2019 04:53:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57758) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hiEVD-0003zr-Ho for qemu-devel@nongnu.org; Tue, 02 Jul 2019 04:51:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hiEVC-0007gN-2Y for qemu-devel@nongnu.org; Tue, 02 Jul 2019 04:51:03 -0400 Received: from mga06.intel.com ([134.134.136.31]:27257) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hiEVB-0007A5-Nq for qemu-devel@nongnu.org; Tue, 02 Jul 2019 04:51:01 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Jul 2019 01:49:59 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,442,1557212400"; d="scan'208";a="184453392" Received: from richard.sh.intel.com (HELO localhost) ([10.239.159.54]) by fmsmga001.fm.intel.com with ESMTP; 02 Jul 2019 01:49:56 -0700 Date: Tue, 2 Jul 2019 16:49:34 +0800 From: Wei Yang To: Pankaj Gupta Message-ID: <20190702084934.GA25987@richard> References: <20190619094907.10131-1-pagupta@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190619094907.10131-1-pagupta@redhat.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 134.134.136.31 Subject: Re: [Qemu-devel] [PATCH v2 0/7] Qemu virtio pmem device X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Wei Yang Cc: kwolf@redhat.com, aarcange@redhat.com, nilal@redhat.com, xiaoguangrong.eric@gmail.com, mst@redhat.com, rth@twiddle.net, cohuck@redhat.com, david@redhat.com, qemu-devel@nongnu.org, armbru@redhat.com, stefanha@redhat.com, imammedo@redhat.com, pbonzini@redhat.com, riel@surriel.com, lcapitulino@redhat.com, dan.j.williams@intel.com, dgilbert@redhat.com, ehabkost@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Jun 19, 2019 at 03:19:00PM +0530, Pankaj Gupta wrote: > This patch series has implementation for "virtio pmem" > device. "virtio pmem" is persistent memory(nvdimm) device in > guest which allows to bypass the guest page cache. This > also implements a VIRTIO based asynchronous flush mechanism. > Details of project idea for 'virtio pmem' flushing interface > is shared [2] & [3]. > > Sharing Qemu device emulation in this patchset. Tested with > guest kernel driver [1]. This series is based on David's > memory device refactoring [5] work with modified version of > my initial virtio pmem [4] series. > > Usage: > ./qemu -name test -machine pc -m 8G,slots=240,maxmem=20G > -object memory-backend-file,id=mem1,share,mem-path=test.img, > size=4G,share > -device virtio-pmem-pci,memdev=mem1,id=nv1 > Hi, Pankaj I tried this series with v14 kernel driver, while getting some error on using this. Not sure this is my error configuration. The qemu command line is: -object memory-backend-file,id=mem1,share=on,mem-path=/dev/dax0.0,size=1G,align=2M -device virtio-pmem-pci,memdev=mem1,id=nv1 The guest boots up and I can see /dev/pmem0 device. But when I want to partition this device, I got the error: # parted /dev/pmem0 mklabel gpt Warning: Error fsyncing/closing /dev/pmem0: Input/output error Also I see an error when running "ndctl list": libndctl: __sysfs_device_parse: ndctl0: add_dev() failed Would you mind letting me know which part I am wrong? > (qemu) info memory-devices > Memory device [virtio-pmem]: "nv1" > memaddr: 0x240000000 > size: 4294967296 > memdev: /objects/mem1 > > Implementation is divided into two parts: > New virtio pmem guest driver and qemu code changes for new > virtio pmem paravirtualized device. In this series we are > sharing Qemu device emulation. > >1. Guest virtio-pmem kernel driver >--------------------------------- > - Reads persistent memory range from paravirt device and > registers with 'nvdimm_bus'. > - 'nvdimm/pmem' driver uses this information to allocate > persistent memory region and setup filesystem operations > to the allocated memory. > - virtio pmem driver implements asynchronous flushing > interface to flush from guest to host. > >2. Qemu virtio-pmem device >--------------------------------- > - Creates virtio pmem device and exposes a memory range to > KVM guest. > - At host side this is file backed memory which acts as > persistent memory. > - Qemu side flush uses aio thread pool API's and virtio > for asynchronous guest multi request handling. > > Virtio-pmem security implications and suggested countermeasures: > --------------------------------------------------------------- > > In previous posting of kernel driver, there was discussion [7] > on possible implications of page cache side channel attacks with > virtio pmem. After thorough analysis of details of known side > channel attacks, below are the suggestions: > > - Depends entirely on how host backing image file is mapped > into guest address space. > > - virtio-pmem device emulation, by default shared mapping is used > to map host backing file. It is recommended to use separate > backing file at host side for every guest. This will prevent > any possibility of executing common code from multiple guests > and any chance of inferring guest local data based based on > execution time. > > - If backing file is required to be shared among multiple guests > it is recommended to don't support host page cache eviction > commands from the guest driver. This will avoid any possibility > of inferring guest local data or host data from another guest. > > - Proposed device specification [6] for virtio-pmem device with > details of possible security implications and suggested > countermeasures for device emulation. > >Changes from PATCH v1: > - Change proposed version from qemu 4.0 to 4.1 - Eric > - Remove virtio queue_add from unrealize function - Cornelia > >[1] https://lkml.org/lkml/2019/6/12/624 >[2] https://www.spinics.net/lists/kvm/msg149761.html >[3] https://www.spinics.net/lists/kvm/msg153095.html >[4] https://marc.info/?l=linux-kernel&m=153572228719237&w=2 >[5] https://marc.info/?l=qemu-devel&m=153555721901824&w=2 >[6] https://lists.oasis-open.org/archives/virtio-dev/201903/msg00083.html >[7] https://lkml.org/lkml/2019/1/9/1191 > > Pankaj Gupta (3): > virtio-pmem: add virtio device > virtio-pmem: sync linux headers > virtio-pci: proxy for virtio-pmem > > David Hildenbrand (4): > virtio-pci: Allow to specify additional interfaces for the base type > hmp: Handle virtio-pmem when printing memory device infos > numa: Handle virtio-pmem in NUMA stats > pc: Support for virtio-pmem-pci > > hmp.c | 27 ++- > hw/i386/Kconfig | 1 > hw/i386/pc.c | 72 ++++++++++ > hw/virtio/Kconfig | 10 + > hw/virtio/Makefile.objs | 2 > hw/virtio/virtio-pci.c | 1 > hw/virtio/virtio-pci.h | 1 > hw/virtio/virtio-pmem-pci.c | 131 ++++++++++++++++++ > hw/virtio/virtio-pmem-pci.h | 34 ++++ > hw/virtio/virtio-pmem.c | 189 +++++++++++++++++++++++++++ > include/hw/pci/pci.h | 1 > include/hw/virtio/virtio-pmem.h | 49 +++++++ > include/standard-headers/linux/virtio_ids.h | 1 > include/standard-headers/linux/virtio_pmem.h | 35 +++++ > numa.c | 24 +-- > qapi/misc.json | 28 +++- > 16 files changed, 580 insertions(+), 26 deletions(-) >---- -- Wei Yang Help you, Help me