Although virtio scsi specification was designed as a replacement for virtio_blk,
there are still many users using virtio_blk. Qemu 2.9 introduced a new device
vhost user scsi which can process I/O in user space for virtio_scsi, this commit
introduces a new vhost user block host device, which can support virtio_blk in
Guest OS, and I/O processing in another I/O target.

Due to the limitation for virtio_blk specification, virtio_blk device cannot get
block information such as capacity, block size etc via the specification, several
new vhost user messages were added to support deliver virtio config space
information between Qemu and I/O target, VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG
messages used for get/set config space from/to I/O target, VHOST_USER_SET_CONFIG_FD
was added for event notifier in case the change of virtio config space. Also, those
messages can be used for vhost device live migration as well.

Changpeng Liu (4):
  vhost-user: add new vhost user messages to support virtio config space
  vhost-user-blk: introduce a new vhost-user-blk host device
  contrib/libvhost-user: enable virtio config space messages
  contrib/vhost-user-blk: introduce a vhost-user-blk sample application

 .gitignore                              |   1 +
 Makefile                                |   3 +
 Makefile.objs                           |   2 +
 configure                               |  11 +
 contrib/libvhost-user/libvhost-user.c   |  74 ++++
 contrib/libvhost-user/libvhost-user.h   |  15 +
 contrib/vhost-user-blk/Makefile.objs    |   1 +
 contrib/vhost-user-blk/vhost-user-blk.c | 735 ++++++++++++++++++++++++++++++++
 docs/interop/vhost-user.txt             |  32 ++
 hw/block/Makefile.objs                  |   3 +
 hw/block/vhost-user-blk.c               | 360 ++++++++++++++++
 hw/virtio/vhost-user.c                  |  97 +++++
 hw/virtio/vhost.c                       |  63 +++
 hw/virtio/virtio-pci.c                  |  55 +++
 hw/virtio/virtio-pci.h                  |  18 +
 include/hw/virtio/vhost-backend.h       |   8 +
 include/hw/virtio/vhost-user-blk.h      |  40 ++
 include/hw/virtio/vhost.h               |  16 +
 18 files changed, 1534 insertions(+)
 create mode 100644 contrib/vhost-user-blk/Makefile.objs
 create mode 100644 contrib/vhost-user-blk/vhost-user-blk.c
 create mode 100644 hw/block/vhost-user-blk.c
 create mode 100644 include/hw/virtio/vhost-user-blk.h

-- 
1.9.3

On 09/12/2017 02:56 AM, Changpeng Liu wrote:
   ^^^^^^^^^^^^^^^^^^^

Wow, your system clock is off.  According to the mail headers:

> Received: from orsmga004.jf.intel.com ([10.7.209.38])
> 	by fmsmga105.fm.intel.com with ESMTP; 11 Sep 2017 00:36:13 -0700
...
> Date: Tue, 12 Sep 2017 15:56:12 +0800

the intel.com machine received it at 7:36 UTC Monday, even though your
computer sent it at 9:56 UTC Tuesday, 26 hours in the future.  Sending
mail from the future messes with clients that like to display mail
sorted by date of last activity in the thread.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org