[Qemu-devel] [PATCH 00/18] Kemari for KVM v0.2.14

[OHMURA Kei]

Hi,

This patch series is a revised version of Kemari for KVM. The current 
code is based on qemu.git ec444452b8753a372de30b22d9b4765a799db612.

The changes from v0.2.13 -> v0.2.14 are:

- rebased to latest.
- correct patch[07], [09] author.

The changes from v0.2.12 -> v0.2.13 are:

- replaced qemu_get_timer() with qemu_get_timer_ns()
- check check s->file before calling qemu_ft_trans_cancel()
- avoid virtio-net assert upon calling event_tap_unregister()

The changes from v0.2.11 -> v0.2.12 are:

- fix vm_state_notify() to use QLIST_FOREACH_SAFE (Juan)
- introduce qemu_loadvm_state_no_header() and refactored
 qemu_loadvm_state() to call it after checking headers (Juan)

The changes from v0.2.10 -> v0.2.11 are:

- rebased to 0.14
- upon unregistering event-tap, set event_tap_state after event_tap_flush
- modify commit log of 02/18 that it won't make existing migration
 bi-directional.

The changes from v0.2.9 -> v0.2.10 are:

- change migrate format to kemari:<protocol>:<host>:<port> (Paolo)

The changes from v0.2.8 -> v0.2.9 are:

- abstract common code between qemu_savevm_{state,trans}_* (Paolo)
- change incoming format to kemari:<protocol>:<host>:<port> (Paolo)

The changes from v0.2.7 -> v0.2.8 are:

- fixed calling wrong cb in event-tap
- add missing qemu_aio_release in event-tap

The changes from v0.2.6 -> v0.2.7 are:

- add AIOCB, AIOPool and cancel functions (Kevin)
- insert event-tap for bdrv_flush (Kevin)
- add error handing when calling bdrv functions (Kevin)
- fix usage of qemu_aio_flush and bdrv_flush (Kevin)
- use bs in AIOCB on the primary (Kevin)
- reorder event-tap functions to gather with block/net (Kevin)
- fix checking bs->device_name (Kevin)

The changes from v0.2.5 -> v0.2.6 are:

- use qemu_{put,get}_be32() to save/load niov in event-tap

The changes from v0.2.4 -> v0.2.5 are:

- fixed braces and trailing spaces by using Blue's checkpatch.pl (Blue)
- event-tap: don't try to send blk_req if it's a bdrv_aio_flush event

The changes from v0.2.3 -> v0.2.4 are:

- call vm_start() before event_tap_flush_one() to avoid failure in
 virtio-net assertion
- add vm_change_state_handler to turn off ft_mode
- use qemu_iovec functions in event-tap
- remove duplicated code in migration
- remove unnecessary new line for error_report in ft_trans_file

The changes from v0.2.2 -> v0.2.3 are:

- queue async net requests without copying (MST)
-- if not async, contents of the packets are sent to the secondary
- better description for option -k (MST)
- fix memory transfer failure
- fix ft transaction initiation failure

The changes from v0.2.1 -> v0.2.2 are:

- decrement last_avaid_idx with inuse before saving (MST)
- remove qemu_aio_flush() and bdrv_flush_all() in migrate_ft_trans_commit()

The changes from v0.2 -> v0.2.1 are:

- Move event-tap to net/block layer and use stubs (Blue, Paul, MST, Kevin)
- Tap bdrv_aio_flush (Marcelo)
- Remove multiwrite interface in event-tap (Stefan)
- Fix event-tap to use pio/mmio to replay both net/block (Stefan)
- Improve error handling in event-tap (Stefan)
- Fix leak in event-tap (Stefan)
- Revise virtio last_avail_idx manipulation (MST)
- Clean up migration.c hook (Marcelo)
- Make deleting change state handler robust (Isaku, Anthony)

The changes from v0.1.1 -> v0.2 are:

- Introduce a queue in event-tap to make VM sync live.
- Change transaction receiver to a state machine for async receiving.
- Replace net/block layer functions with event-tap proxy functions.
- Remove dirty bitmap optimization for now.
- convert DPRINTF() in ft_trans_file to trace functions.
- convert fprintf() in ft_trans_file to error_report().
- improved error handling in ft_trans_file.
- add a tmp pointer to qemu_del_vm_change_state_handler.

The changes from v0.1 -> v0.1.1 are:

- events are tapped in net/block layer instead of device emulation layer.
- Introduce a new option for -incoming to accept FT transaction.

- Removed writev() support to QEMUFile and FdMigrationState for now.
 I would post this work in a different series.

- Modified virtio-blk save/load handler to send inuse variable to
 correctly replay.

- Removed configure --enable-ft-mode.
- Removed unnecessary check for qemu_realloc().

The first 6 patches modify several functions of qemu to prepare
introducing Kemari specific components.

The next 6 patches are the components of Kemari.  They introduce
event-tap and the FT transaction protocol file based on buffered file.
The design document of FT transaction protocol can be found at,
http://wiki.qemu.org/images/b/b1/Kemari_sender_receiver_0.5a.pdf

Then the following 2 patches modifies net/block layer functions with
event-tap functions.  Please note that if Kemari is off, event-tap
will just passthrough, and there is most no intrusion to exisiting
functions including normal live migration.

Finally, the migration layer are modified to support Kemari in the
last 4 patches.  Again, there shouldn't be any affection if a user
doesn't specify Kemari specific options.  The transaction is now async
on both sender and receiver side.  The sender side respects the
max_downtime to decide when to switch from async to sync mode.

The repository contains all patches I'm sending with this message.
For those who want to try, please pull the following repository.  It
also includes dirty bitmap optimization which aren't ready for posting
yet.  To remove the dirty bitmap optimization, please look at HEAD~5
of the tree.

git://kemari.git.sourceforge.net/gitroot/kemari/kemari next

Thanks,

Kei


OHMURA Kei (2):
  Introduce fault tolerant VM transaction QEMUFile and ft_mode.
  Introduce event-tap.

Yoshiaki Tamura (16):
  Make QEMUFile buf expandable, and introduce qemu_realloc_buffer() and
    qemu_clear_buffer().
  Introduce read() to FdMigrationState.
  Introduce qemu_loadvm_state_no_header() and make qemu_loadvm_state()
    a wrapper.
  qemu-char: export socket_set_nodelay().
  vl.c: add deleted flag for deleting the handler.
  virtio: decrement last_avail_idx with inuse before saving.
  savevm: introduce util functions to control ft_trans_file from savevm
    layer.
  Call init handler of event-tap at main() in vl.c.
  ioport: insert event_tap_ioport() to ioport_write().
  Insert event_tap_mmio() to cpu_physical_memory_rw() in exec.c.
  net: insert event-tap to qemu_send_packet() and
    qemu_sendv_packet_async().
  block: insert event-tap to bdrv_aio_writev(), bdrv_aio_flush() and
    bdrv_flush().
  savevm: introduce qemu_savevm_trans_{begin,commit}.
  migration: introduce migrate_ft_trans_{put,get}_ready(), and modify
    migrate_fd_put_ready() when ft_mode is on.
  migration-tcp: modify tcp_accept_incoming_migration() to handle
    ft_mode, and add a hack not to close fd when ft_mode is enabled.
  Introduce "kemari:" to enable FT migration mode (Kemari).

 Makefile.objs   |    1 +
 Makefile.target |    1 +
 block.c         |   15 +
 event-tap.c     |  940 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 event-tap.h     |   44 +++
 exec.c          |    4 +
 ft_trans_file.c |  624 ++++++++++++++++++++++++++++++++++++
 ft_trans_file.h |   72 +++++
 hmp-commands.hx |    4 +-
 hw/hw.h         |    7 +
 hw/virtio.c     |   10 +-
 ioport.c        |    2 +
 migration-tcp.c |   83 +++++-
 migration.c     |  294 +++++++++++++++++-
 migration.h     |    3 +
 net.c           |    9 +
 qemu-char.c     |    2 +-
 qemu-tool.c     |   28 ++
 qemu_socket.h   |    1 +
 qmp-commands.hx |    4 +-
 savevm.c        |  372 +++++++++++++++++-----
 sysemu.h        |    2 +
 trace-events    |   25 ++
 vl.c            |   18 +-
 24 files changed, 2477 insertions(+), 88 deletions(-)
 create mode 100644 event-tap.c
 create mode 100644 event-tap.h
 create mode 100644 ft_trans_file.c
 create mode 100644 ft_trans_file.h