[Qemu-devel] [RFC PATCH v4 00/28] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service

[zhanghailiang]

This is the 4th version of COLO, here is only COLO frame part, include: VM 
checkpoint,
failover, proxy API, block replication API, not include block replication.
The block part has been sent by wencongyang:
[RFC PATCH COLO v2 00/13] Block replication for continuous checkpoints

Compared with last version, there aren't too much optimize and new functions.
The main reason is that there is an known issue that still unsolved, we found
some dirty pages which have been missed setting bit in corresponding bitmap.
And it will trigger strange problem in VM.
We hope to resolve it before add more codes.

You can get the newest integrated qemu colo patches from github:
https://github.com/coloft/qemu/commits/colo-v1.1

About how to test COLO, Please reference to the follow link.
http://wiki.qemu.org/Features/COLO.

Please review and test.

Known issue still unsolved:
(1) Some pages dirtied without setting its corresponding dirty-bitmap.

Previous posted RFC patch series:
http://lists.nongnu.org/archive/html/qemu-devel/2014-06/msg05567.html
http://lists.nongnu.org/archive/html/qemu-devel/2014-09/msg04459.html
https://lists.gnu.org/archive/html/qemu-devel/2015-02/msg04771.html

TODO list:
1 Optimize the process of checkpoint, shorten the time-consuming:
  (Partly done, patch is not include into this series)
   1) separate ram and device save/load process to reduce size of extra memory
      used during checkpoint
   2) live migrate part of dirty pages to slave during sleep time.
2 Add more debug/stat info
  (Partly done, patch is not include into this series)
  include checkpoint count, proxy discompare count, downtime,
   number of live migrated pages, total sent pages, etc.
3 Strengthen failover
4 optimize proxy part, include proxy script.
5 The capability of continuous FT

v4:
- New block replication scheme (use image-fleecing for sencondary side)
- Adress some comments from Eric Blake and Dave
- Add commmand colo-set-checkpoint-period to set the time of periodic checkpoint
- Add a delay (100ms) between continuous checkpoint requests to ensure VM
  run 100ms at least since last pause.

v3:
- use proxy instead of colo agent to compare network packets
- add block replication
- Optimize failover disposal
- handle shutdown

v2:
- use QEMUSizedBuffer/QEMUFile as COLO buffer
- colo support is enabled by default
- add nic replication support
- addressed comments from Eric Blake and Dr. David Alan Gilbert

v1:
- implement the frame of colo

Wen Congyang (1):
  COLO: Add block replication into colo process

zhanghailiang (27):
  configure: Add parameter for configure to enable/disable COLO support
  migration: Introduce capability 'colo' to migration
  COLO: migrate colo related info to slave
  migration: Integrate COLO checkpoint process into migration
  migration: Integrate COLO checkpoint process into loadvm
  COLO: Implement colo checkpoint protocol
  COLO: Add a new RunState RUN_STATE_COLO
  QEMUSizedBuffer: Introduce two help functions for qsb
  COLO: Save VM state to slave when do checkpoint
  COLO RAM: Load PVM's dirty page into SVM's RAM cache temporarily
  COLO VMstate: Load VM state into qsb before restore it
  arch_init: Start to trace dirty pages of SVM
  COLO RAM: Flush cached RAM into SVM's memory
  COLO failover: Introduce a new command to trigger a failover
  COLO failover: Implement COLO master/slave failover work
  COLO failover: Don't do failover during loading VM's state
  COLO: Add new command parameter 'colo_nicname' 'colo_script' for net
  COLO NIC: Init/remove colo nic devices when add/cleanup tap devices
  COLO NIC: Implement colo nic device interface configure()
  COLO NIC : Implement colo nic init/destroy function
  COLO NIC: Some init work related with proxy module
  COLO: Do checkpoint according to the result of net packets comparing
  COLO: Improve checkpoint efficiency by do additional periodic
    checkpoint
  COLO: Add colo-set-checkpoint-period command
  COLO NIC: Implement NIC checkpoint and failover
  COLO: Disable qdev hotplug when VM is in COLO mode
  COLO: Implement shutdown checkpoint

 arch_init.c                            | 199 +++++++-
 configure                              |  14 +
 hmp-commands.hx                        |  30 ++
 hmp.c                                  |  14 +
 hmp.h                                  |   2 +
 include/exec/cpu-all.h                 |   1 +
 include/migration/migration-colo.h     |  58 +++
 include/migration/migration-failover.h |  22 +
 include/migration/migration.h          |   3 +
 include/migration/qemu-file.h          |   3 +-
 include/net/colo-nic.h                 |  25 +
 include/net/net.h                      |   4 +
 include/sysemu/sysemu.h                |   3 +
 migration/Makefile.objs                |   2 +
 migration/colo-comm.c                  |  80 ++++
 migration/colo-failover.c              |  48 ++
 migration/colo.c                       | 809 +++++++++++++++++++++++++++++++++
 migration/migration.c                  |  60 ++-
 migration/qemu-file-buf.c              |  58 +++
 net/Makefile.objs                      |   1 +
 net/colo-nic.c                         | 438 ++++++++++++++++++
 net/tap.c                              |  45 +-
 qapi-schema.json                       |  42 +-
 qemu-options.hx                        |  10 +-
 qmp-commands.hx                        |  41 ++
 savevm.c                               |   2 +-
 scripts/colo-proxy-script.sh           |  97 ++++
 stubs/Makefile.objs                    |   1 +
 stubs/migration-colo.c                 |  58 +++
 vl.c                                   |  36 +-
 30 files changed, 2178 insertions(+), 28 deletions(-)
 create mode 100644 include/migration/migration-colo.h
 create mode 100644 include/migration/migration-failover.h
 create mode 100644 include/net/colo-nic.h
 create mode 100644 migration/colo-comm.c
 create mode 100644 migration/colo-failover.c
 create mode 100644 migration/colo.c
 create mode 100644 migration/colo.c.
 create mode 100644 net/colo-nic.c
 create mode 100755 scripts/colo-proxy-script.sh
 create mode 100644 stubs/migration-colo.c

-- 
1.7.12.4