[PATCH 0/4] Multiple interface support on top of Multi-FD

[Het Gala]

As of now, the multi-FD feature supports connection over the default network
only. This Patchset series is a Qemu side implementation of providing multiple
interfaces support for multi-FD. This enables us to fully utilize dedicated or
multiple NICs in case bonding of NICs is not possible.


Introduction
-------------
Multi-FD Qemu implementation currently supports connection only on the default
network. This forbids us from advantages like:
- Separating VM live migration traffic from the default network.
- Fully utilize all NICs’ capacity in cases where creating a LACP bond (Link
  Aggregation Control Protocol) is not supported.

Multi-interface with Multi-FD
-----------------------------
Multiple-interface support over basic multi-FD has been implemented in the
patches. Advantages of this implementation are:
- Able to separate live migration traffic from default network interface by
  creating multiFD channels on ip addresses of multiple non-default interfaces.
- Can optimize the number of multi-FD channels on a particular interface
  depending upon the network bandwidth limit on a particular interface.

Implementation
--------------

Earlier the 'migrate' qmp command:
{ "execute": "migrate", "arguments": { "uri": "tcp:0:4446" } }

Modified qmp command:
{ "execute": "migrate",
             "arguments": { "uri": "tcp:0:4446", "multi-fd-uri-list": [ {
             "source-uri": "tcp::6900", "destination-uri": "tcp:0:4480",
             "multifd-channels": 4}, { "source-uri": "tcp:10.0.0.0: ",
             "destination-uri": "tcp:11.0.0.0:7789",
             "multifd-channels": 5} ] } }
------------------------------------------------------------------------------

Earlier the 'migrate-incoming' qmp command:
{ "execute": "migrate-incoming", "arguments": { "uri": "tcp::4446" } }

Modified 'migrate-incoming' qmp command:
{ "execute": "migrate-incoming",
            "arguments": {"uri": "tcp::6789",
            "multi-fd-uri-list" : [ {"destination-uri" : "tcp::6900",
            "multifd-channels": 4}, {"destination-uri" : "tcp:11.0.0.0:7789",
            "multifd-channels": 5} ] } }
------------------------------------------------------------------------------

Introduced a new flag while spawning a qemu process for 'migrate-incoming' ip
addresses (-multi-fd-incoming flag):
-multi-fd-incoming "tcp::6900:4,tcp:11.0.0.0:7789:5"

---
Het Gala (4):
  Modifying ‘migrate’ qmp command to add multi-FD socket on particular
    source and destination pair
  Adding multi-interface support for multi-FD on destination side
  Establishing connection between any non-default source and destination
    pair
  Adding support for multi-FD connections dynamically

 chardev/char-socket.c               |   4 +-
 include/io/channel-socket.h         |  26 ++--
 include/qapi/util.h                 |  10 ++
 include/qemu/sockets.h              |   6 +-
 io/channel-socket.c                 |  50 +++++--
 migration/migration.c               | 211 ++++++++++++++++++++++------
 migration/migration.h               |   3 +-
 migration/multifd.c                 |  42 +++---
 migration/socket.c                  | 119 ++++++++++++----
 migration/socket.h                  |  24 +++-
 monitor/hmp-cmds.c                  |  68 ++++-----
 nbd/client-connection.c             |   2 +-
 qapi/migration.json                 |  92 +++++++++---
 qapi/qapi-util.c                    |  27 ++++
 qemu-nbd.c                          |   4 +-
 qemu-options.hx                     |  18 +++
 scsi/pr-manager-helper.c            |   1 +
 softmmu/vl.c                        |  30 +++-
 tests/unit/test-char.c              |   8 +-
 tests/unit/test-io-channel-socket.c |   4 +-
 tests/unit/test-util-sockets.c      |  16 +--
 ui/input-barrier.c                  |   2 +-
 ui/vnc.c                            |   3 +-
 util/qemu-sockets.c                 |  71 +++++++---
 24 files changed, 626 insertions(+), 215 deletions(-)

-- 
2.22.3