[Qemu-devel] [PATCH for-4.0 0/6] vhost-user-blk: Add support for backend reconnecting

[elohimes]

From: Xie Yongji <address@hidden>

This patchset is aimed at supporting qemu to reconnect
vhost-user-blk backend after vhost-user-blk backend crash or
restart.

The patch 1 tries to implenment the sync connection for
"reconnect socket".

The patch 2 introduces a new message VHOST_USER_SET_VRING_INFLIGHT
to support offering shared memory to backend to record
its inflight I/O.

The patch 3,4 are the corresponding libvhost-user patches of
patch 2. Make libvhost-user support VHOST_USER_SET_VRING_INFLIGHT.

The patch 5 supports vhost-user-blk to reconnect backend when
connection closed.

The patch 6 tells qemu that we support reconnecting now.

To use it, we could start qemu with:

qemu-system-x86_64 \
        -chardev socket,id=char0,path=/path/vhost.socket,reconnect=1,wait \
        -device vhost-user-blk-pci,chardev=char0 \

and start vhost-user-blk backend with:

vhost-user-blk -b /path/file -s /path/vhost.socket

Then we can restart vhost-user-blk at any time during VM running.

Xie Yongji (6):
  char-socket: Enable "wait" option for client mode
  vhost-user: Add shared memory to record inflight I/O
  libvhost-user: Introduce vu_queue_map_desc()
  libvhost-user: Support recording inflight I/O in shared memory
  vhost-user-blk: Add support for reconnecting backend
  contrib/vhost-user-blk: enable inflight I/O recording

 chardev/char-socket.c                   |   5 +-
 contrib/libvhost-user/libvhost-user.c   | 215 ++++++++++++++++++++----
 contrib/libvhost-user/libvhost-user.h   |  19 +++
 contrib/vhost-user-blk/vhost-user-blk.c |   3 +-
 hw/block/vhost-user-blk.c               | 169 +++++++++++++++++--
 hw/virtio/vhost-user.c                  |  69 ++++++++
 hw/virtio/vhost.c                       |   8 +
 include/hw/virtio/vhost-backend.h       |   4 +
 include/hw/virtio/vhost-user-blk.h      |   4 +
 include/hw/virtio/vhost-user.h          |   8 +
 10 files changed, 452 insertions(+), 52 deletions(-)

-- 
2.17.1