Re: [Qemu-devel] [v8 13/14] migration: Add qmp commands to set and query parameters

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

* Liang Li (liang.z.li@intel.com) wrote:
> Add the qmp commands to tune and query the parameters used in live
> migration.

Hi,
  Do you know if there's anyone working on libvirt code to drive this
interface and turn on your compression code?

Dave

> 
> Signed-off-by: Liang Li <liang.z.li@intel.com>
> Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
> ---
>  migration/migration.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  qapi-schema.json      | 45 ++++++++++++++++++++++++++++++++++++++++
>  qmp-commands.hx       | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 158 insertions(+)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 533717c..8732803 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -188,6 +188,21 @@ MigrationCapabilityStatusList *qmp_query_migrate_capabilities(Error **errp)
>      return head;
>  }
>  
> +MigrationParameters *qmp_query_migrate_parameters(Error **errp)
> +{
> +    MigrationParameters *params;
> +    MigrationState *s = migrate_get_current();
> +
> +    params = g_malloc0(sizeof(*params));
> +    params->compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
> +    params->compress_threads =
> +            s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
> +    params->decompress_threads =
> +            s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
> +
> +    return params;
> +}
> +
>  static void get_xbzrle_cache_stats(MigrationInfo *info)
>  {
>      if (migrate_use_xbzrle()) {
> @@ -301,6 +316,47 @@ void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
>      }
>  }
>  
> +void qmp_migrate_set_parameters(bool has_compress_level,
> +                                int64_t compress_level,
> +                                bool has_compress_threads,
> +                                int64_t compress_threads,
> +                                bool has_decompress_threads,
> +                                int64_t decompress_threads, Error **errp)
> +{
> +    MigrationState *s = migrate_get_current();
> +
> +    if (has_compress_level && (compress_level < 0 || compress_level > 9)) {
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
> +                  "a value in range [0, 9]");
> +        return;
> +    }
> +    if (has_compress_threads &&
> +        (compress_threads < 1 || compress_threads > 255)) {
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE,
> +                  "compress_threads",
> +                  "a value in range [1, 255]");
> +        return;
> +    }
> +    if (has_decompress_threads &&
> +        (decompress_threads < 1 || decompress_threads > 255)) {
> +        error_set(errp, QERR_INVALID_PARAMETER_VALUE,
> +                  "decompress_threads",
> +                  "a value in range [1, 255]");
> +        return;
> +    }
> +
> +    if (has_compress_level) {
> +        s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
> +    }
> +    if (has_compress_threads) {
> +        s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] = compress_threads;
> +    }
> +    if (has_decompress_threads) {
> +        s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
> +                                                    decompress_threads;
> +    }
> +}
> +
>  /* shared migration helpers */
>  
>  static void migrate_set_state(MigrationState *s, int old_state, int new_state)
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 121fcc7..579801b 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -592,6 +592,51 @@
>  { 'enum': 'MigrationParameter',
>    'data': ['compress-level', 'compress-threads', 'decompress-threads'] }
>  
> +#
> +# @migrate-set-parameters
> +#
> +# Set the following migration parameters
> +#
> +# @compress-level: compression level
> +#
> +# @compress-threads: compression thread count
> +#
> +# @decompress-threads: decompression thread count
> +#
> +# Since: 2.3
> +##
> +{ 'command': 'migrate-set-parameters',
> +  'data': { '*compress-level': 'int',
> +            '*compress-threads': 'int',
> +            '*decompress-threads': 'int'} }
> +
> +#
> +# @MigrationParameters
> +#
> +# @compress-level: compression level
> +#
> +# @compress-threads: compression thread count
> +#
> +# @decompress-threads: decompression thread count
> +#
> +# Since: 2.3
> +##
> +{ 'type': 'MigrationParameters',
> +  'data': { 'compress-level': 'int',
> +            'compress-threads': 'int',
> +            'decompress-threads': 'int'} }
> +##
> +# @query-migrate-parameters
> +#
> +# Returns information about the current migration parameters
> +#
> +# Returns: @MigrationParameters
> +#
> +# Since: 2.3
> +##
> +{ 'command': 'query-migrate-parameters',
> +  'returns': 'MigrationParameters' }
> +
>  ##
>  # @MouseInfo:
>  #
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 3a42ad0..8fcf5a8 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -3320,6 +3320,63 @@ EQMP
>      },
>  
>  SQMP
> +migrate-set-parameters
> +----------------------
> +
> +Set migration parameters
> +
> +- "compress-level": set compression level during migration (json-int)
> +- "compress-threads": set compression thread count for migration (json-int)
> +- "decompress-threads": set decompression thread count for migration (json-int)
> +
> +Arguments:
> +
> +Example:
> +
> +-> { "execute": "migrate-set-parameters" , "arguments":
> +      { "compress-level": 1 } }
> +
> +EQMP
> +
> +    {
> +        .name       = "migrate-set-parameters",
> +        .args_type  =
> +            "compress-level:i?,compress-threads:i?,decompress-threads:i?",
> +	.mhandler.cmd_new = qmp_marshal_input_migrate_set_parameters,
> +    },
> +SQMP
> +query-migrate-parameters
> +------------------------
> +
> +Query current migration parameters
> +
> +- "parameters": migration parameters value
> +         - "compress-level" : compression level value (json-int)
> +         - "compress-threads" : compression thread count value (json-int)
> +         - "decompress-threads" : decompression thread count value (json-int)
> +
> +Arguments:
> +
> +Example:
> +
> +-> { "execute": "query-migrate-parameters" }
> +<- {
> +      "return": {
> +         "decompress-threads", 2,
> +         "compress-threads", 8,
> +         "compress-level", 1
> +      }
> +   }
> +
> +EQMP
> +
> +    {
> +        .name       = "query-migrate-parameters",
> +        .args_type  = "",
> +        .mhandler.cmd_new = qmp_marshal_input_query_migrate_parameters,
> +    },
> +
> +SQMP
>  query-balloon
>  -------------
>  
> -- 
> 1.9.1
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK