From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pankaj Gupta Subject: Re: [Qemu-devel] [RFC v3] qemu: Add virtio pmem device Date: Wed, 25 Jul 2018 01:01:39 -0400 (EDT) Message-ID: <399916154.53931292.1532494899706.JavaMail.zimbra@redhat.com> References: <20180713075232.9575-1-pagupta@redhat.com> <20180713075232.9575-4-pagupta@redhat.com> <783786ae-2e85-2376-448c-1e362c3d4d48@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <783786ae-2e85-2376-448c-1e362c3d4d48-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: kwolf-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, nilal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, jack-AlSwsSmVLrQ@public.gmane.org, xiaoguangrong eric , kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, riel-ebMLmSuQjDVBDgjK7y7TUQ@public.gmane.org, linux-nvdimm-y27Ovi1pjclAfugRpC6u6w@public.gmane.org, david-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, ross zwisler , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, qemu-devel-qX2TKyscuCcdnm+yROfE0A@public.gmane.org, hch-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, pbonzini-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, stefanha-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, niteshnarayanlal-PkbjNfxxIARBDgjK7y7TUQ@public.gmane.org, imammedo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, lcapitulino-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org List-Id: linux-nvdimm@lists.01.org Hi Eric, > > On 07/13/2018 02:52 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. > > > > Changes from RFC v2: > > This patch has no n/M in the subject line; but is included in a thread > that also has a 0/2 cover letter, as well as 1/2 and 2/2 patches in > separate mails. Is that intentional? Yes, kernel series has 0-2 patches and Qemu has this one. I thought its good to keep separate numbering for both the sets. > > When sending revision notes on a specific patch, it's best to place them... Sure. > > > - Use aio_worker() to avoid Qemu from hanging with blocking fsync > > call - Stefan > > - Use virtio_st*_p() for endianess - Stefan > > - Correct indentation in qapi/misc.json - Eric > > > > Signed-off-by: Pankaj Gupta > > --- > > ...here, after the --- separator. They are useful to reviewers on the > list, but are stripped by 'git am' as they don't need to be part of the > git history (a year from now, we won't care how many iterations the > patch went through during review, only what actually landed). > > > > +++ b/qapi/misc.json > > @@ -2907,6 +2907,29 @@ > > } > > } > > > > +## > > +# @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 > > There is no 2.13 release, and you've missed the 3.0 window. Please > update this and any other version reference to 3.1. okay. Thanks, Pankaj