Re: [Qemu-devel] [PATCH 0/17 v4] Localhost migration with side channel for ram

[Paolo Bonzini <pbonzini@redhat.com>]

Il 29/11/2013 11:06, Lei Li ha scritto:
> This patch series tries to introduce a mechanism using side
> channel pipe for RAM via SCM_RIGHTS with unix domain socket
> protocol migration.
> 
> This side channel is used for the page flipping by vmsplice,
> which is the internal mechanism for localhost migration that
> we are trying to add to QEMU. The backgroud info and previous
> patch series for reference,
> 
> Localhost migration
> http://lists.nongnu.org/archive/html/qemu-devel/2013-08/msg02916.html
> 
> migration: Introduce side channel for RAM
> http://lists.gnu.org/archive/html/qemu-devel/2013-09/msg04043.html
> 
> I have picked patches from the localhost migration series and rebased 
> it on the series of side channel, now it is a complete series that
> passed the basic test.

One change: please rename the capability to x-unix-page-flipping for
now.  No need to rename the function migrate_unix_page_flipping(), only
the capability name in qapi-schema.json (and references to the enum
MIGRATION_CAPABILITY_UNIX_PAGE_FLIPPING).

With that change, v5 will get "Reviewed-by: Paolo Bonzini
<pbonzini@redhat.com>".

Thanks!

Paolo

> Please let me know if there is anything needs to be fixed or improved.
> Your suggestions and comments are very welcome, and thanks to Paolo
> for his continued review and useful suggestions.
> 
> Changes since V3:
>   Address comments from Paolo including:
> 
>     - Get rid of useless check in send_pipefd() and the override
>       of before_ram_iterate, send pipefd in the first save_page
>       call, qemu_get_byte() in the first ram_load correspondingly.
>     - Add new argument ram_addr_t to hook_ram_load to cut half of
>       the data transferred on the socket.
>     - Add transition from 'debug' to 'memory-stale'.
>     - Other minor fixes.
> 
> Changes since V2:
>   Address comments from Paolo including:
> 
>     - Doc improvement for QAPI.
>     - Use callback get_buffer as the only one receiver.
>     - Rename the new RunState flipping-migrate to memory-stale, and
>       add transition from 'prelaunch' to 'memory-stale'.
>     - Other minor fixes.
> 
> Changes since V1:
>   Address suggestions from Paolo Bonzini including:
> 
>     - Use Unix socket QEMUFile as basis of code and adjust the way
>       of overriding RDMA hooks.
>     - Involve the vmsplice for page flipping.
>     - Add new RunState RUN_STATE_FLIPPING_MIGRATE and add it to
>       runstate_needs_reset() for the adjustment of the current
>       migration process with page flipping.
> 
> 
> 
> Lei Li (17):
>   QAPI: introduce magration capability unix_page_flipping
>   migration: add migrate_unix_page_flipping()
>   qmp-command.hx: add missing docs for migration capabilites
>   migration-local: add QEMUFileLocal with socket based QEMUFile
>   migration-local: introduce qemu_fopen_socket_local()
>   migration-local: add send_pipefd()
>   save_page: replace block_offset with a MemoryRegion
>   migration-local: override save_page for page transmit
>   savevm: adjust ram_control_save_page with page flipping
>   add unix_msgfd_lookup() to callback get_buffer
>   add argument ram_addr_t to hook_ram_load
>   migration-local: override hook_ram_load 
>   migration-unix: replace qemu_fopen_socket with qemu_fopen_socket_local
>   add new RanState RAN_STATE_MEMORY_STALE
>   migration-unix: page flipping support on unix outgoing
>   migration: adjust migration_thread() process for unix_page_flipping
>   hmp: better fomat for info migrate_capabilities
> 
>  Makefile.target               |   1 +
>  arch_init.c                   |   4 +-
>  migration-local.c             | 512 ++++++++++++++++++++++++++++++++++++++++++
>  hmp.c                         |   5 +-
>  include/migration/migration.h |   3 +
>  include/migration/qemu-file.h |   2 +
>  migration-unix.c              |  27 ++-
>  migration-rdma.c              |   4 +-
>  migration.c                   |  18 +-
>  qapi-schema.json              |  18 +-
>  qmp-commands.hx               |   8 +
>  savevm.c                      |  21 +-
>  vl.c                          |  12 +-
>  13 files changed, 617 insertions(+), 27 deletions(-)
>  create mode 100644 migration-local.c
>