From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pankaj Gupta Subject: Re: [Qemu-devel] [RFC v2] qemu: Add virtio pmem device Date: Wed, 25 Apr 2018 10:55:57 -0400 (EDT) Message-ID: <634642140.22649359.1524668157371.JavaMail.zimbra@redhat.com> References: <20180425112415.12327-1-pagupta@redhat.com> <20180425112415.12327-4-pagupta@redhat.com> <25f3e433-cfa6-4a62-ba7f-47aef1119dfc@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <25f3e433-cfa6-4a62-ba7f-47aef1119dfc-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Eric Blake Cc: jack-AlSwsSmVLrQ@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, david-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-nvdimm-y27Ovi1pjclAfugRpC6u6w@public.gmane.org, ross zwisler , qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org, lcapitulino-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, niteshnarayanlal-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org, mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, marcel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, nilal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, riel-ebMLmSuQjDVBDgjK7y7TUQ@public.gmane.org, stefanha-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, kwolf-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, xiaoguangrong eric , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, imammedo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org List-Id: linux-nvdimm@lists.01.org > > On 04/25/2018 06:24 AM, Pankaj Gupta wrote: > > This patch adds virtio-pmem Qemu device. > > > > This device presents memory address range > > information to guest which is backed by file > > backend type. It acts like persistent memory > > device for KVM guest. Guest can perform read > > and persistent write operations on this memory > > range with the help of DAX capable filesystem. > > > > Persistent guest writes are assured with the > > help of virtio based flushing interface. When > > guest userspace space performs fsync on file > > fd on pmem device, a flush command is send to > > Qemu over VIRTIO and host side flush/sync is > > done on backing image file. > > > > This PV device code is dependent and tested > > with 'David Hildenbrand's ' patchset[1] to > > map non-PCDIMM devices to guest address space. > > This sentence doesn't belong in git history. It is better to put > information like this... > > > There is still upstream discussion on using > > among PCI bar vs memory device, will update > > as per concensus. > > s/concensus/consensus/ > > > > > [1] https://marc.info/?l=qemu-devel&m=152450249319168&w=2 > > > > Signed-off-by: Pankaj Gupta > > --- > > ...here, where it is part of the email, but not picked up by 'git am'. I see. Thanks! > > > > +++ b/qapi/misc.json > > @@ -2871,6 +2871,29 @@ > > } > > } > > > > +## > > +# @VirtioPMemDeviceInfo: > > +# > > +# VirtioPMem state information > > +# > > +# @id: device's ID > > +# > > +# @start: physical address, where device is mapped > > +# > > +# @size: size of memory that the device provides > > +# > > +# @memdev: memory backend linked with device > > +# > > +# Since: 2.13 > > +## > > +{ 'struct': 'VirtioPMemDeviceInfo', > > + 'data': { '*id': 'str', > > + 'start': 'size', > > + 'size': 'size', > > TAB damage. o.k > > > + 'memdev': 'str' > > + } > > +} > > + > > ## > > # @MemoryDeviceInfo: > > # > > @@ -2880,7 +2903,8 @@ > > ## > > { 'union': 'MemoryDeviceInfo', > > 'data': { 'dimm': 'PCDIMMDeviceInfo', > > - 'nvdimm': 'PCDIMMDeviceInfo' > > + 'nvdimm': 'PCDIMMDeviceInfo', > > + 'virtio-pmem': 'VirtioPMemDeviceInfo' > > } > > } > > > > > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org > >