From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45626) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fudHz-0001KW-Fb for qemu-devel@nongnu.org; Tue, 28 Aug 2018 08:40:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fudHt-0003XY-IR for qemu-devel@nongnu.org; Tue, 28 Aug 2018 08:40:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56372) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fudHt-0003Ft-8k for qemu-devel@nongnu.org; Tue, 28 Aug 2018 08:40:01 -0400 Date: Tue, 28 Aug 2018 08:39:53 -0400 (EDT) From: Pankaj Gupta Message-ID: <16583366.7193885.1535459993521.JavaMail.zimbra@redhat.com> In-Reply-To: <1328e543-0276-8f33-1744-8baa053023c4@redhat.com> References: <20180713075232.9575-1-pagupta@redhat.com> <1328e543-0276-8f33-1744-8baa053023c4@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC v3 0/2] kvm "fake DAX" device flushing List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, linux-nvdimm@ml01.01.org, kwolf@redhat.com, haozhong zhang , jack@suse.cz, xiaoguangrong eric , riel@surriel.com, niteshnarayanlal@hotmail.com, mst@redhat.com, ross zwisler , lcapitulino@redhat.com, hch@infradead.org, stefanha@redhat.com, imammedo@redhat.com, pbonzini@redhat.com, dan j williams , nilal@redhat.com Hi David, > > for review. This patchset has two parts: > > > > - Guest virtio-pmem driver > > Guest driver reads persistent memory range from paravirt device > > and registers with 'nvdimm_bus'. 'nvdimm/pmem' driver uses this > > information to allocate persistent memory range. Also, we have > > implemented guest side of VIRTIO flushing interface. > > > > - Qemu virtio-pmem device > > It exposes a persistent memory range to KVM guest which at host > > side is file backed memory and works as persistent memory device. > > In addition to this it provides virtio device handling of flushing > > interface. KVM guest performs Qemu side asynchronous sync using > > this interface. > > > > Changes from RFC v2: > > - Add flush function in the nd_region in place of switching > > on a flag - Dan & Stefan > > - Add flush completion function with proper locking and wait > > for host side flush completion - Stefan & Dan > > - Keep userspace API in uapi header file - Stefan, MST > > - Use LE fields & New device id - MST > > - Indentation & spacing suggestions - MST & Eric > > - Remove extra header files & add licensing - Stefan > > > > Changes from RFC v1: > > - Reuse existing 'pmem' code for registering persistent > > memory and other operations instead of creating an entirely > > new block driver. > > - Use VIRTIO driver to register memory information with > > nvdimm_bus and create region_type accordingly. > > - Call VIRTIO flush from existing pmem driver. > > > > Details of project idea for 'fake DAX' flushing interface is > > shared [2] & [3]. > > > > Pankaj Gupta (2): > > Add virtio-pmem guest driver > > pmem: device flush over VIRTIO > > > > [1] https://marc.info/?l=linux-mm&m=150782346802290&w=2 > > [2] https://www.spinics.net/lists/kvm/msg149761.html > > [3] https://www.spinics.net/lists/kvm/msg153095.html > > > > drivers/nvdimm/nd.h | 1 > > drivers/nvdimm/pmem.c | 4 > > drivers/nvdimm/region_devs.c | 24 +++- > > drivers/virtio/Kconfig | 9 + > > drivers/virtio/Makefile | 1 > > drivers/virtio/virtio_pmem.c | 190 > > +++++++++++++++++++++++++++++++++++++++ > > include/linux/libnvdimm.h | 5 - > > include/linux/virtio_pmem.h | 44 +++++++++ > > include/uapi/linux/virtio_ids.h | 1 > > include/uapi/linux/virtio_pmem.h | 40 ++++++++ > > 10 files changed, 310 insertions(+), 9 deletions(-) > > > > Hi Pankaj, > > do you have a branch for the QEMU part somewhere available? I want to > see how this works with MemoryDevice changes. o.k I will update the guest virtio-pmem and Qemu current changes and share with you. BTW previous version is here: https://marc.info/?l=kvm&m=153146839627143&w=2 Thanks, Pankaj > > -- > > Thanks, > > David / dhildenb > >