Re: [Qemu-devel] [PATCH COLO-Frame v17 00/34] COarse-grain LOck-stepping(COLO) Virtual Machines for Non-stop Service (FT)

["Dr. David Alan Gilbert" <dgilbert@redhat.com>]

* zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
> This is the 17th version of COLO FT feature.
> 
> Here is only COLO frame part, you can get the whole codes from github:
> https://github.com/coloft/qemu/commits/colo-v3.0-periodic-mode
> 
> Migration now switches to use the new QIOChannel API. It only affects COLO's
> patch 9 and patch 12, which we used the old qsb buffer before, and we updated
> them with the new API. It's only involving tiny changes.

I notice that the block code has nearly been accepted; so perhaps it's
worth posting a version rebased on the current rc and then hopefully
we can line this core code up for the start of 2.8 as soon as the block
code lands.

Dave

> Patch status:
> Unreviewed: patch 32 ~ 35
> Updated: patch 9, 12, 32
> 
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Cc: Jeff Cody <jcody@redhat.com>
> Cc: Kevin Wolf <kwolf@redhat.com>
> Cc: Max Reitz <mreitz@redhat.com>
> Cc: Juan Quintela <quintela@redhat.com>
> Cc: Amit Shah <amit.shah@redhat.com>
> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> 
> PS: These series has been in community for a long time, it depends on
> Changlong's block-replicaton series, but that has been blocked for a long
> time, we really need help on reviewing that and this series.  Thanks.
> 
> TODO:
> 1. Checkpoint based on proxy in qemu
> 2. The capability of continuous FT
> 3. Optimize the VM's downtime during checkpoint
> 
> v17:
>  - Rebase master to use the new QIOChannel API, only affect patch 9 and 12
>  - Reorganize some ugly comments
>  - Rename colo_sem to colo_exit_sem (patch 21)
> 
> v16:
>  - Fix compile broken due to missing osdep.h
>  - Add reviewed-by tag for patch 27, 28, 29
>  - Rename the message send/receive helper function (patch 7, 13)
>  - Simplify the codes by using some notifier helpers in QEMU (patch 32)
>  - Remove the useless check in colo_add_buffer_filter() (patch 33)
>  - Remove the previous patch 36, 37 which export filter_buffer_flush()
>    to release the buffered packets, we simplify it by stopping buffer 
>    filter while doing checkpoint, which will flush the buffered packets
>    by default. (patch 34)
> v15:
>  - Go on the shutdown process if encounter error while sending shutdown
>    message to SVM. (patch 24)
>  - Rename qemu_need_skip_netfilter to qemu_netfilter_can_skip and Remove
>    some useless comment. (patch 31, Jason)
>  - Call object_new_with_props() directly to add filter in
>    colo_add_buffer_filter. (patch 34, Jason)
>  - Re-implement colo_set_filter_status() based on COLOBufferFilters
>    list. (patch 35)
>  - Re-implement colo_flush_filter_packets() based on COLOBufferFilters
>    list. (patch 37) 
> v14:
>  - Re-implement the network processing based on netfilter (Jason Wang)
>  - Rename 'COLOCommand' to 'COLOMessage'. (Markus's suggestion)
>  - Split two new patches (patch 27/28) from patch 29
>  - Fix some other comments from Dave and Markus.
> 
> v13:
>  - Refactor colo_*_cmd helper functions to use 'Error **errp' parameter
>   instead of return value to indicate success or failure. (patch 10)
>  - Remove the optional error message for COLO_EXIT event. (patch 25)
>  - Use semaphore to notify colo/colo incoming loop that failover work is
>    finished. (patch 26)
>  - Move COLO shutdown related codes to colo.c file. (patch 28)
>  - Fix memory leak bug for colo incoming loop. (new patch 31)
>  - Re-use some existed helper functions to realize the process of
>    saving/loading ram and device. (patch 32)
>  - Fix some other comments from Dave and Markus.
> 
> 
> zhanghailiang (34):
>   configure: Add parameter for configure to enable/disable COLO support
>   migration: Introduce capability 'x-colo' to migration
>   COLO: migrate colo related info to secondary node
>   migration: Integrate COLO checkpoint process into migration
>   migration: Integrate COLO checkpoint process into loadvm
>   COLO/migration: Create a new communication path from destination to
>     source
>   COLO: Implement COLO checkpoint protocol
>   COLO: Add a new RunState RUN_STATE_COLO
>   COLO: Save PVM state to secondary side when do checkpoint
>   COLO: Load PVM's dirty pages into SVM's RAM cache temporarily
>   ram/COLO: Record the dirty pages that SVM received
>   COLO: Load VMState into buffer before restore it
>   COLO: Flush PVM's cached RAM into SVM's memory
>   COLO: Add checkpoint-delay parameter for migrate-set-parameters
>   COLO: Synchronize PVM's state to SVM periodically
>   COLO failover: Introduce a new command to trigger a failover
>   COLO failover: Introduce state to record failover process
>   COLO: Implement failover work for Primary VM
>   COLO: Implement failover work for Secondary VM
>   qmp event: Add COLO_EXIT event to notify users while exited from COLO
>   COLO failover: Shutdown related socket fd when do failover
>   COLO failover: Don't do failover during loading VM's state
>   COLO: Process shutdown command for VM in COLO state
>   COLO: Update the global runstate after going into colo state
>   savevm: Introduce two helper functions for save/find loadvm_handlers
>     entry
>   migration/savevm: Add new helpers to process the different stages of
>     loadvm
>   migration/savevm: Export two helper functions for savevm process
>   COLO: Separate the process of saving/loading ram and device state
>   COLO: Split qemu_savevm_state_begin out of checkpoint process
>   filter-buffer: Accept zero interval
>   net: Add notifier/callback for netdev init
>   COLO/filter: Add each netdev a buffer filter
>   COLO: Control the status of buffer filters for PVM
>   COLO: Add block replication into colo process
> 
>  configure                     |  11 +
>  docs/qmp-events.txt           |  16 +
>  hmp-commands.hx               |  15 +
>  hmp.c                         |  15 +
>  hmp.h                         |   1 +
>  include/exec/ram_addr.h       |   1 +
>  include/migration/colo.h      |  43 +++
>  include/migration/failover.h  |  33 ++
>  include/migration/migration.h |  16 +
>  include/net/filter.h          |   2 +
>  include/net/net.h             |   3 +
>  include/sysemu/sysemu.h       |   9 +
>  migration/Makefile.objs       |   2 +
>  migration/colo-comm.c         |  79 ++++
>  migration/colo-failover.c     |  84 +++++
>  migration/colo.c              | 844 ++++++++++++++++++++++++++++++++++++++++++
>  migration/migration.c         |  84 ++++-
>  migration/ram.c               | 175 ++++++++-
>  migration/savevm.c            | 114 ++++--
>  net/filter-buffer.c           |  12 -
>  net/net.c                     |  12 +
>  qapi-schema.json              | 102 ++++-
>  qapi/event.json               |  15 +
>  qmp-commands.hx               |  24 +-
>  stubs/Makefile.objs           |   1 +
>  stubs/migration-colo.c        |  55 +++
>  trace-events                  |   8 +
>  vl.c                          |  31 +-
>  28 files changed, 1744 insertions(+), 63 deletions(-)
>  create mode 100644 include/migration/colo.h
>  create mode 100644 include/migration/failover.h
>  create mode 100644 migration/colo-comm.c
>  create mode 100644 migration/colo-failover.c
>  create mode 100644 migration/colo.c
>  create mode 100644 stubs/migration-colo.c
> 
> -- 
> 1.8.3.1
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK