[Qemu-devel] [RFC PATCH 00/13] Embedded NBD server

[Paolo Bonzini <pbonzini@redhat.com>]

Hi all,

this is an RFC series implementing an NBD server embedded inside QEMU.
This can be used in various cases, including migration with non-shared
storage.

Three new commands are introduced at the QMP level

  { 'command': 'nbd-server-start',  'data': { 'addr': 'IPSocketAddress' } }
  { 'command': 'nbd-server-add', 'data': {'device': 'str', '*writable': 'bool'} }
  { 'command': 'nbd-server-stop' }

At the HMP level there is no nbd_server_add command.  nbd_server_start
automatically exposes all of the VM's block devices, and an option -w
makes them writable.

The NBD server exports multiple devices on a single port; they can be
accessed using "nbd:HOST:PART:exportname=NAME".

The patches are mostly boring touching nbd.c.  The part where I need
a second opinion and/or ack is patch 12 and 13.  They fix the case of
a disk being unplugged while NBD export is active.  To do this I add a
NotifierList to a BlockDriverState.  Does this look okay, or is it too
ad hoc?

Paolo Bonzini (13):
  nbd: add more constants
  nbd: pass NBDClient to nbd_send_negotiate
  nbd: do not leak nbd_trip coroutines when a connection is torn down
  nbd: close all clients on deleting export
  nbd: register named exports
  nbd: negotiate with named exports
  nbd: do not close BlockDriverState in nbd_export_close
  qemu-sockets: publish dummy_opts
  qmp: add NBD server commands
  qemu-sockets: make inet_parse public
  hmp: add NBD server commands
  block: add close notifiers
  nbd: add notifier to close exports when the image is closed

 Makefile.objs       |   5 +-
 block.c             |  19 +++-
 block.h             |   1 +
 block_int.h         |   2 +
 blockdev-nbd.c      | 131 ++++++++++++++++++++++
 hmp-commands.hx     |  29 +++++
 hmp.c               |  66 +++++++++++
 hmp.h               |   2 +
 nbd.c               | 311 +++++++++++++++++++++++++++++++++++++++++-----------
 nbd.h               |   6 +
 qapi-schema.json    |  69 ++++++++++++
 qapi/opts-visitor.c |  48 ++++----
 qemu-nbd.c          |   1 +
 qemu-sockets.c      |  16 +--
 qemu_socket.h       |   3 +
 qmp-commands.hx     |  16 +++
 16 file modificati, 621 inserzioni(+), 104 rimozioni(-)
 create mode 100644 blockdev-nbd.c

-- 
1.7.11.2