Re: [Qemu-devel] [PATCH v2] Move migrate_set_speed and migrate_set_downtime into migrate_set_parameter

[Paolo Bonzini]

On 05/09/2016 13:37, Ashijeet Acharya wrote:
> Include migrate_set_speed and migrate_set_downtime inside 
> migrate_set_parameters for setting maximum migration speed and expected 
> downtime parameters respectively. Also update the query part for both in qmp 
> and hmp qemu control interfaces.
> 
> Signed-off-by: Ashijeet Acharya <address@hidden>
> ---
>  hmp-commands.hx               |  6 +++---
>  hmp.c                         | 30 +++++++++++++++++++++++++++++-
>  include/migration/migration.h |  1 -
>  migration/migration.c         | 30 ++++++++++++++++++++++++++----
>  qapi-schema.json              | 26 +++++++++++++++++++++++---
>  qmp-commands.hx               | 13 ++++++++++---
>  6 files changed, 91 insertions(+), 15 deletions(-)
> 
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index 848efee..4dc7899 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1009,15 +1009,15 @@ ETEXI
>  
>      {
>          .name       = "migrate_set_parameter",
> -        .args_type  = "parameter:s,value:s",
> -        .params     = "parameter value",
> +        .args_type  = "parameter:s,value:s?,speed:o?",
> +        .params     = "parameter value speed",
>          .help       = "Set the parameter for migration",
>          .mhandler.cmd = hmp_migrate_set_parameter,
>          .command_completion = migrate_set_parameter_completion,
>      },
>  
>  STEXI
> address@hidden migrate_set_parameter @var{parameter} @var{value}
> address@hidden migrate_set_parameter @var{parameter} @var{value} @var{speed}

This is wrong, it should not use a third argument.
migrate_set_parameter is just receiving a key/value pair.

Since value is a string, you can use qemu_strtosz in
hmp_migrate_set_parameter to convert it to bytes and print an "invalid
size" error if invalid.

>  @findex migrate_set_parameter
>  Set the parameter @var{parameter} for migration.
>  ETEXI
> diff --git a/hmp.c b/hmp.c
> index cc2056e..fd50e83 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -304,6 +304,12 @@ void hmp_info_migrate_parameters(Monitor *mon, const 
> QDict *qdict)
>          monitor_printf(mon, " %s: '%s'",
>              MigrationParameter_lookup[MIGRATION_PARAMETER_TLS_HOSTNAME],
>              params->tls_hostname ? : "");
> +        monitor_printf(mon, " %s: %" PRId64,
> +            MigrationParameter_lookup[MIGRATION_PARAMETER_MIGRATE_SET_SPEED],
> +            params->migrate_set_speed);
> +        monitor_printf(mon, " %s: %" PRId64,
> +            
> MigrationParameter_lookup[MIGRATION_PARAMETER_MIGRATE_SET_DOWNTIME],
> +            params->migrate_set_downtime);
>          monitor_printf(mon, "\n");
>      }
>  
> @@ -1193,6 +1199,7 @@ void hmp_migrate_incoming(Monitor *mon, const QDict 
> *qdict)
>      hmp_handle_error(mon, &err);
>  }
>  
> +/* Kept for old-commands compatibility */
>  void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict)
>  {
>      double value = qdict_get_double(qdict, "value");
> @@ -1211,6 +1218,7 @@ void hmp_migrate_set_cache_size(Monitor *mon, const 
> QDict *qdict)
>      }
>  }
>  
> +/* Kept for old-commands compatibility */
>  void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict)
>  {
>      int64_t value = qdict_get_int(qdict, "value");
> @@ -1250,8 +1258,11 @@ void hmp_migrate_set_capability(Monitor *mon, const 
> QDict *qdict)
>  void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
>  {
>      const char *param = qdict_get_str(qdict, "parameter");
> -    const char *valuestr = qdict_get_str(qdict, "value");
> +    const char *valuestr = qdict_get_try_str(qdict, "value");
> +    int64_t valuespeed = 0;
> +    double valuedowntime = 0;
>      long valueint = 0;
> +    char *endp;
>      Error *err = NULL;
>      bool has_compress_level = false;
>      bool has_compress_threads = false;
> @@ -1260,6 +1271,8 @@ void hmp_migrate_set_parameter(Monitor *mon, const 
> QDict *qdict)
>      bool has_cpu_throttle_increment = false;
>      bool has_tls_creds = false;
>      bool has_tls_hostname = false;
> +    bool has_migrate_set_speed = false;
> +    bool has_migrate_set_downtime = false;
>      bool use_int_value = false;
>      int i;
>  
> @@ -1291,6 +1304,19 @@ void hmp_migrate_set_parameter(Monitor *mon, const 
> QDict *qdict)
>              case MIGRATION_PARAMETER_TLS_HOSTNAME:
>                  has_tls_hostname = true;
>                  break;
> +            case MIGRATION_PARAMETER_MIGRATE_SET_SPEED:
> +                has_migrate_set_speed = true;
> +                valuespeed = qdict_get_int(qdict, "speed");
> +                break;
> +            case MIGRATION_PARAMETER_MIGRATE_SET_DOWNTIME:
> +                has_migrate_set_downtime = true;
> +                valuedowntime = strtod(valuestr, &endp);
> +                if (valuestr == endp) {
> +                    error_setg(&err, "Unable to parse '%s' as a number",
> +                               valuestr);
> +                    goto cleanup;
> +                }
> +                break;
>              }
>  
>              if (use_int_value) {
> @@ -89,6 +91,8 @@ MigrationState *migrate_get_current(void)
>              .decompress_threads = DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
>              .cpu_throttle_initial = DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL,
>              .cpu_throttle_increment = DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT,
> +            .migrate_set_speed = MAX_THROTTLE,
> +            .migrate_set_downtime = DEFAULT_MIGRATE_SET_DOWNTIME,
>          },
>      };
>  
> @@ -566,6 +570,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error 
> **errp)
>      params->cpu_throttle_increment = s->parameters.cpu_throttle_increment;
>      params->tls_creds = g_strdup(s->parameters.tls_creds);
>      params->tls_hostname = g_strdup(s->parameters.tls_hostname);
> +    params->migrate_set_speed = s->parameters.migrate_set_speed;
> +    params->migrate_set_downtime = s->parameters.migrate_set_downtime;
>  
>      return params;
>  }
> @@ -773,6 +779,10 @@ void qmp_migrate_set_parameters(bool has_compress_level,
>                                  const char *tls_creds,
>                                  bool has_tls_hostname,
>                                  const char *tls_hostname,
> +                                bool has_migrate_set_speed,
> +                                int64_t migrate_set_speed,
> +                                bool has_migrate_set_downtime,
> +                                double migrate_set_downtime,
>                                  Error **errp)
>  {
>      MigrationState *s = migrate_get_current();
> @@ -832,6 +842,12 @@ void qmp_migrate_set_parameters(bool has_compress_level,
>          g_free(s->parameters.tls_hostname);
>          s->parameters.tls_hostname = g_strdup(tls_hostname);
>      }
> +    if (has_migrate_set_speed) {
> +        qmp_migrate_set_speed(migrate_set_speed, NULL);
> +    }
> +    if (has_migrate_set_downtime) {
> +        qmp_migrate_set_downtime(migrate_set_downtime, NULL);
> +    }

This is backwards; qmp_migrate_set_speed and qmp_migrate_set_downtime
should be implemented in terms of qmp_migrate_set_parameters, not the
other way round.

>  }
>  
>  
> @@ -1175,18 +1191,24 @@ void qmp_migrate_set_speed(int64_t value, Error 
> **errp)
>      }
>  
>      s = migrate_get_current();
> -    s->bandwidth_limit = value;
> +    s->parameters.migrate_set_speed = value;
>      if (s->to_dst_file) {
>          qemu_file_set_rate_limit(s->to_dst_file,
> -                                 s->bandwidth_limit / XFER_LIMIT_RATIO);
> +                            s->parameters.migrate_set_speed / 
> XFER_LIMIT_RATIO);
>      }
>  }
>  
>  void qmp_migrate_set_downtime(double value, Error **errp)
>  {
> +    MigrationState *s;
> +
>      value *= 1e9;
>      value = MAX(0, MIN(UINT64_MAX, value));
> +
> +    s = migrate_get_current();
> +
>      max_downtime = (uint64_t)value;
> +    s->parameters.migrate_set_downtime = max_downtime;
>  }
>  
>  bool migrate_postcopy_ram(void)
> @@ -1858,7 +1880,7 @@ void migrate_fd_connect(MigrationState *s)
>  
>      qemu_file_set_blocking(s->to_dst_file, true);
>      qemu_file_set_rate_limit(s->to_dst_file,
> -                             s->bandwidth_limit / XFER_LIMIT_RATIO);
> +                             s->parameters.migrate_set_speed / 
> XFER_LIMIT_RATIO);
>  
>      /* Notify before starting migration thread */
>      notifier_list_notify(&migration_state_notifiers, s);
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 5658723..b98be44 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -637,12 +637,18 @@
>  #                hostname must be provided so that the server's x509
>  #                certificate identity can be validated. (Since 2.7)
>  #
> +# @migrate-set-speed: to set maximum speed for migration. A value lesser than
> +#                     zero will be automatically round upto zero.
> +#
> +# @migrate-set-downtime: set maximum tolerated downtime for migration.

Please add "Since 2.8" to the documentation for the new members.

> +#
>  # Since: 2.4
>  ##
>  { 'enum': 'MigrationParameter',
>    'data': ['compress-level', 'compress-threads', 'decompress-threads',
>             'cpu-throttle-initial', 'cpu-throttle-increment',
> -           'tls-creds', 'tls-hostname'] }
> +           'tls-creds', 'tls-hostname', 'migrate-set-speed',
> +           'migrate-set-downtime'] }

MigrationParameter names are not verbs.  It should be "downtime-limit"
and "max-bandwidth", or something similar.

>  
>  #
>  # @migrate-set-parameters
> @@ -678,6 +684,11 @@
>  #                hostname must be provided so that the server's x509
>  #                certificate identity can be validated. (Since 2.7)
>  #
> +# @migrate-set-speed: to set maximum speed for migration. A value lesser than
> +#                     zero will be automatically round upto zero.
> +#
> +# @migrate-set-downtime: set maximum tolerated downtime for migration.
> +#
>  # Since: 2.4
>  ##
>  { 'command': 'migrate-set-parameters',
> @@ -687,7 +698,9 @@
>              '*cpu-throttle-initial': 'int',
>              '*cpu-throttle-increment': 'int',
>              '*tls-creds': 'str',
> -            '*tls-hostname': 'str'} }
> +            '*tls-hostname': 'str',
> +            '*migrate-set-speed': 'int',
> +            '*migrate-set-downtime': 'number'} }

Same here.

>  
>  #
>  # @MigrationParameters
> @@ -721,6 +734,11 @@
>  #                hostname must be provided so that the server's x509
>  #                certificate identity can be validated. (Since 2.7)
>  #
> +# @migrate-set-speed: to set maximum speed for migration. A value lesser than
> +#                     zero will be automatically round upto zero.
> +#
> +# @migrate-set-downtime: set maximum tolerated downtime for migration.

Same here, note that these are "Since 2.8".

> +#
>  # Since: 2.4
>  ##
>  { 'struct': 'MigrationParameters',
> @@ -730,7 +748,9 @@
>              'cpu-throttle-initial': 'int',
>              'cpu-throttle-increment': 'int',
>              'tls-creds': 'str',
> -            'tls-hostname': 'str'} }
> +            'tls-hostname': 'str',
> +            'migrate-set-speed': 'int',
> +            'migrate-set-downtime': 'int'} }

Same here about the names.

>  ##
>  # @query-migrate-parameters
>  #
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 6866264..c4d3809 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -3790,7 +3790,9 @@ Set migration parameters
>                            throttled for auto-converge (json-int)
>  - "cpu-throttle-increment": set throttle increasing percentage for
>                              auto-converge (json-int)
> -
> +- "migrate-set-speed": set maximum speed for migrations (json-octets)
> +- "migrate-set-downtime": set maximum tolerated downtime (in seconds) for
> +                          migrations (json-number)

Same here about the names.

>  Arguments:
>  
>  Example:
> @@ -3803,7 +3805,7 @@ EQMP
>      {
>          .name       = "migrate-set-parameters",
>          .args_type  =
> -            
> "compress-level:i?,compress-threads:i?,decompress-threads:i?,cpu-throttle-initial:i?,cpu-throttle-increment:i?",
> +            
> "compress-level:i?,compress-threads:i?,decompress-threads:i?,cpu-throttle-initial:i?,cpu-throttle-increment:i?,migrate-set-speed:o?,migrate-set-downtime:T?",

Same here about the names.  Also use "i" for QMP commands.

>          .mhandler.cmd_new = qmp_marshal_migrate_set_parameters,
>      },
>  SQMP
> @@ -3820,6 +3822,9 @@ Query current migration parameters
>                                      throttled (json-int)
>           - "cpu-throttle-increment" : throttle increasing percentage for
>                                        auto-converge (json-int)
> +         - "migrate-set-speed" : maximium migration speed (json-octets)
> +         - "migration-set-downtime" : maximum tolerated downtime of migration
> +                                      (json-number)

Same here about the names.

>  Arguments:
>  
> @@ -3832,7 +3837,9 @@ Example:
>           "cpu-throttle-increment": 10,
>           "compress-threads": 8,
>           "compress-level": 1,
> -         "cpu-throttle-initial": 20
> +         "cpu-throttle-initial": 20,
> +         "migration-set-speed": 33554432,
> +         "migration-set-downtime": 300000000

Same here about the names.

>        }
>     }
>  
>