Re: [Qemu-devel] [PATCH 01/11] Add migration capabilities

[Luiz Capitulino <lcapitulino@redhat.com>]

On Sun, 29 Jul 2012 12:42:53 +0300
Orit Wasserman <owasserm@redhat.com> wrote:

> Add migration capabilities that can be queried by the management.
> The management can query the source QEMU and the destination QEMU in order to
> verify both support some migration capability (currently only XBZRLE).
> 
> Signed-off-by: Orit Wasserman <owasserm@redhat.com>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> ---
>  hmp-commands.hx  |    2 ++
>  hmp.c            |   19 +++++++++++++++++++
>  hmp.h            |    1 +
>  migration.c      |   11 +++++++++++
>  monitor.c        |    7 +++++++
>  qapi-schema.json |   39 +++++++++++++++++++++++++++++++++++++++
>  qmp-commands.hx  |   24 ++++++++++++++++++++++++
>  7 files changed, 103 insertions(+), 0 deletions(-)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index eea8b32..8786148 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1417,6 +1417,8 @@ show CPU statistics
>  show user network stack connection states
>  @item info migrate
>  show migration status
> +@item info migration_capabilities
> +show migration capabilities
>  @item info balloon
>  show balloon information
>  @item info qtree
> diff --git a/hmp.c b/hmp.c
> index 6b72a64..5c7d0be 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -161,6 +161,25 @@ void hmp_info_migrate(Monitor *mon)
>      qapi_free_MigrationInfo(info);
>  }
>  
> +void hmp_info_migration_capabilities(Monitor *mon)
> +{
> +    MigrationCapabilityStatusList *caps_list, *cap;
> +
> +    caps_list = qmp_query_migration_capabilities(NULL);
> +    if (!caps_list) {
> +        monitor_printf(mon, "No migration capabilities found\n");
> +        return;
> +    }
> +
> +    for (cap = caps_list; cap; cap = cap->next) {
> +        monitor_printf(mon, "%s: %s ",
> +                       MigrationCapability_lookup[cap->value->capability],
> +                       cap->value->state ? "on" : "off");
> +    }
> +
> +    qapi_free_MigrationCapabilityStatusList(caps_list);
> +}
> +
>  void hmp_info_cpus(Monitor *mon)
>  {
>      CpuInfoList *cpu_list, *cpu;
> diff --git a/hmp.h b/hmp.h
> index 8d2b0d7..2fb44ca 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -25,6 +25,7 @@ void hmp_info_uuid(Monitor *mon);
>  void hmp_info_chardev(Monitor *mon);
>  void hmp_info_mice(Monitor *mon);
>  void hmp_info_migrate(Monitor *mon);
> +void hmp_info_migration_capabilities(Monitor *mon);
>  void hmp_info_cpus(Monitor *mon);
>  void hmp_info_block(Monitor *mon);
>  void hmp_info_blockstats(Monitor *mon);
> diff --git a/migration.c b/migration.c
> index 8db1b43..8c27347 100644
> --- a/migration.c
> +++ b/migration.c
> @@ -166,6 +166,17 @@ MigrationInfo *qmp_query_migrate(Error **errp)
>      return info;
>  }
>  
> +MigrationCapabilityStatusList *qmp_query_migration_capabilities(Error **errp)
> +{
> +    MigrationCapabilityStatusList *caps_list = g_malloc0(sizeof(*caps_list));
> +
> +    caps_list->value = g_malloc(sizeof(*caps_list->value));
> +    caps_list->value->capability = MIGRATION_CAPABILITY_XBZRLE;
> +    caps_list->next = NULL;
> +
> +    return caps_list;
> +}

This is missing an entry in qmp-commands.hx, otherwise looks good.

> +
>  /* shared migration helpers */
>  
>  static int migrate_fd_cleanup(MigrationState *s)
> diff --git a/monitor.c b/monitor.c
> index 09aa3cd..fd57c5e 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -2662,6 +2662,13 @@ static mon_cmd_t info_cmds[] = {
>          .mhandler.info = hmp_info_migrate,
>      },
>      {
> +        .name       = "migration-capabilities",
> +        .args_type  = "",
> +        .params     = "",
> +        .help       = "show migration capabilities",
> +        .mhandler.info = hmp_info_migration_capabilities,
> +    },
> +    {
>          .name       = "balloon",
>          .args_type  = "",
>          .params     = "",
> diff --git a/qapi-schema.json b/qapi-schema.json
> index a92adb1..b4d4dd6 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -306,6 +306,45 @@
>  { 'command': 'query-migrate', 'returns': 'MigrationInfo' }
>  
>  ##
> +# @MigrationCapability
> +#
> +# Migration capabilities enumeration
> +#
> +# @xbzrle: Migration supports xbzrle (Xor Based Zero Length Encoding).
> +#          This feature allows us to minimize migration traffic for certain work
> +#          loads, by sending compressed difference of the pages
> +#
> +# Since: 1.2
> +##
> +{ 'enum': 'MigrationCapability',
> +  'data': ['xbzrle'] }
> +
> +##
> +# @MigrationCapabilityStatus
> +#
> +# Migration capability information
> +#
> +# @capability: capability enum
> +#
> +# @state: capability state bool
> +#
> +# Since: 1.2
> +##
> +{ 'type': 'MigrationCapabilityStatus',
> +  'data': { 'capability' : 'MigrationCapability', 'state' : 'bool' } }
> +
> +##
> +# @query-migration-capabilities
> +#
> +# Returns information about current migration process capabilities.
> +#
> +# Returns: @MigrationCapabilityStatus list
> +#
> +# Since: 1.2
> +##
> +{ 'command': 'query-migration-capabilities', 'returns': ['MigrationCapabilityStatus'] }
> +
> +##
>  # @MouseInfo:
>  #
>  # Information about a mouse device.
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index e3cf3c5..c0ed14c 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -2141,6 +2141,30 @@ EQMP
>      },
>  
>  SQMP
> +query-migration-capabilities
> +-------
> +
> +Query migration capabilities
> +
> +- "xbzrle": xbzrle support
> +
> +Arguments:
> +
> +Example:
> +
> +-> { "execute": "query-migration-capabilities"}
> +<- { "return": [ { "capability": "xbzrle", "state": true },
> +                 { "capability": "foobar", "state": false } ] }
> +
> +EQMP
> +
> +    {
> +        .name       = "query-migration-capabilities",
> +        .args_type  = "",
> +	.mhandler.cmd_new = qmp_marshal_input_query_migration_capabilities,
> +    },
> +
> +SQMP
>  query-balloon
>  -------------
>