Re: [PATCH v2 1/4] migration: Introduce multifd-compression-accel parameter

[Markus Armbruster <armbru@redhat.com>]

Yuan Liu <yuan1.liu@intel.com> writes:

> Introduce the multifd-compression-accel option to enable or disable live
> migration data (de)compression accelerator.
>
> The default value of multifd-compression-accel is auto, and the enabling
> and selection of the accelerator are automatically detected. By setting
> multifd-compression-accel=none, the acceleration function can be disabled.
> Similarly, users can explicitly specify a specific accelerator name, such
> as multifd-compression-accel=qpl.
>
> Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
> Reviewed-by: Nanhai Zou <nanhai.zou@intel.com>
> ---
>  hw/core/qdev-properties-system.c    | 11 +++++++++++
>  include/hw/qdev-properties-system.h |  4 ++++
>  migration/migration-hmp-cmds.c      | 10 ++++++++++
>  migration/options.c                 | 24 ++++++++++++++++++++++++
>  migration/options.h                 |  1 +
>  qapi/migration.json                 | 26 +++++++++++++++++++++++++-
>  6 files changed, 75 insertions(+), 1 deletion(-)
>
> diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
> index 688340610e..ed23035845 100644
> --- a/hw/core/qdev-properties-system.c
> +++ b/hw/core/qdev-properties-system.c
> @@ -673,6 +673,17 @@ const PropertyInfo qdev_prop_multifd_compression = {
>      .set_default_value = qdev_propinfo_set_default_value_enum,
>  };
>
> +/* --- MultiFD Compression Accelerator --- */
> +
> +const PropertyInfo qdev_prop_multifd_compression_accel = {
> +    .name = "MultiFDCompressionAccel",
> +    .description = "MultiFD Compression Accelerator, "
> +                   "auto/none/qpl",
> +    .enum_table = &MultiFDCompressionAccel_lookup,
> +    .get = qdev_propinfo_get_enum,
> +    .set = qdev_propinfo_set_enum,
> +    .set_default_value = qdev_propinfo_set_default_value_enum,
> +};
>  /* --- Reserved Region --- */
>
>  /*
> diff --git a/include/hw/qdev-properties-system.h b/include/hw/qdev-properties-system.h
> index 0ac327ae60..da086bd836 100644
> --- a/include/hw/qdev-properties-system.h
> +++ b/include/hw/qdev-properties-system.h
> @@ -7,6 +7,7 @@ extern const PropertyInfo qdev_prop_chr;
>  extern const PropertyInfo qdev_prop_macaddr;
>  extern const PropertyInfo qdev_prop_reserved_region;
>  extern const PropertyInfo qdev_prop_multifd_compression;
> +extern const PropertyInfo qdev_prop_multifd_compression_accel;
>  extern const PropertyInfo qdev_prop_losttickpolicy;
>  extern const PropertyInfo qdev_prop_blockdev_on_error;
>  extern const PropertyInfo qdev_prop_bios_chs_trans;
> @@ -41,6 +42,9 @@ extern const PropertyInfo qdev_prop_pcie_link_width;
>  #define DEFINE_PROP_MULTIFD_COMPRESSION(_n, _s, _f, _d) \
>      DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_multifd_compression, \
>                         MultiFDCompression)
> +#define DEFINE_PROP_MULTIFD_COMPRESSION_ACCEL(_n, _s, _f, _d) \
> +    DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_multifd_compression_accel, \
> +                       MultiFDCompressionAccel)
>  #define DEFINE_PROP_LOSTTICKPOLICY(_n, _s, _f, _d) \
>      DEFINE_PROP_SIGNED(_n, _s, _f, _d, qdev_prop_losttickpolicy, \
>                          LostTickPolicy)
> diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
> index a82597f18e..3a278c89d9 100644
> --- a/migration/migration-hmp-cmds.c
> +++ b/migration/migration-hmp-cmds.c
> @@ -344,6 +344,11 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
>          monitor_printf(mon, "%s: %s\n",
>              MigrationParameter_str(MIGRATION_PARAMETER_MULTIFD_COMPRESSION),
>              MultiFDCompression_str(params->multifd_compression));
> +        assert(params->has_multifd_compression_accel);
> +        monitor_printf(mon, "%s: %s\n",
> +            MigrationParameter_str(
> +                MIGRATION_PARAMETER_MULTIFD_COMPRESSION_ACCEL),
> +            MultiFDCompressionAccel_str(params->multifd_compression_accel));
>          monitor_printf(mon, "%s: %" PRIu64 " bytes\n",
>              MigrationParameter_str(MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE),
>              params->xbzrle_cache_size);
> @@ -610,6 +615,11 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
>          visit_type_MultiFDCompression(v, param, &p->multifd_compression,
>                                        &err);
>          break;
> +    case MIGRATION_PARAMETER_MULTIFD_COMPRESSION_ACCEL:
> +        p->has_multifd_compression_accel = true;
> +        visit_type_MultiFDCompressionAccel(v, param,
> +                                           &p->multifd_compression_accel, &err);
> +        break;
>      case MIGRATION_PARAMETER_MULTIFD_ZLIB_LEVEL:
>          p->has_multifd_zlib_level = true;
>          visit_type_uint8(v, param, &p->multifd_zlib_level, &err);
> diff --git a/migration/options.c b/migration/options.c
> index 42fb818956..4c567c49e6 100644
> --- a/migration/options.c
> +++ b/migration/options.c
> @@ -59,6 +59,8 @@
>  #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100)
>  #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
>  #define DEFAULT_MIGRATE_MULTIFD_COMPRESSION MULTIFD_COMPRESSION_NONE
> +/* By default use the accelerator for multifd compression */
> +#define DEFAULT_MIGRATE_MULTIFD_COMPRESSION_ACCEL MULTIFD_COMPRESSION_ACCEL_AUTO

The comment is inaccurate.  You could add "when available".  I'd simply
drop the comment.

>  /* 0: means nocompress, 1: best speed, ... 9: best compress ratio */
>  #define DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL 1
>  /* 0: means nocompress, 1: best speed, ... 20: best compress ratio */
> @@ -139,6 +141,9 @@ Property migration_properties[] = {
>      DEFINE_PROP_MULTIFD_COMPRESSION("multifd-compression", MigrationState,
>                        parameters.multifd_compression,
>                        DEFAULT_MIGRATE_MULTIFD_COMPRESSION),
> +    DEFINE_PROP_MULTIFD_COMPRESSION_ACCEL("multifd-compression-accel",
> +                      MigrationState, parameters.multifd_compression_accel,

Break the line after MigrationState for local consistency, please.

> +                      DEFAULT_MIGRATE_MULTIFD_COMPRESSION_ACCEL),
>      DEFINE_PROP_UINT8("multifd-zlib-level", MigrationState,
>                        parameters.multifd_zlib_level,
>                        DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL),
> @@ -818,6 +823,15 @@ MultiFDCompression migrate_multifd_compression(void)
>      return s->parameters.multifd_compression;
>  }
>
> +MultiFDCompressionAccel migrate_multifd_compression_accel(void)
> +{
> +    MigrationState *s = migrate_get_current();
> +
> +    assert(s->parameters.multifd_compression_accel <
> +           MULTIFD_COMPRESSION_ACCEL__MAX);
> +    return s->parameters.multifd_compression_accel;
> +}
> +
>  int migrate_multifd_zlib_level(void)
>  {
>      MigrationState *s = migrate_get_current();
> @@ -945,6 +959,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
>      params->multifd_channels = s->parameters.multifd_channels;
>      params->has_multifd_compression = true;
>      params->multifd_compression = s->parameters.multifd_compression;
> +    params->has_multifd_compression_accel = true;
> +    params->multifd_compression_accel = s->parameters.multifd_compression_accel;
>      params->has_multifd_zlib_level = true;
>      params->multifd_zlib_level = s->parameters.multifd_zlib_level;
>      params->has_multifd_zstd_level = true;
> @@ -999,6 +1015,7 @@ void migrate_params_init(MigrationParameters *params)
>      params->has_block_incremental = true;
>      params->has_multifd_channels = true;
>      params->has_multifd_compression = true;
> +    params->has_multifd_compression_accel = true;
>      params->has_multifd_zlib_level = true;
>      params->has_multifd_zstd_level = true;
>      params->has_xbzrle_cache_size = true;
> @@ -1273,6 +1290,9 @@ static void migrate_params_test_apply(MigrateSetParameters *params,
>      if (params->has_multifd_compression) {
>          dest->multifd_compression = params->multifd_compression;
>      }
> +    if (params->has_multifd_compression_accel) {
> +        dest->multifd_compression_accel = params->multifd_compression_accel;
> +    }
>      if (params->has_xbzrle_cache_size) {
>          dest->xbzrle_cache_size = params->xbzrle_cache_size;
>      }
> @@ -1394,6 +1414,10 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
>      if (params->has_multifd_compression) {
>          s->parameters.multifd_compression = params->multifd_compression;
>      }
> +    if (params->has_multifd_compression_accel) {
> +        s->parameters.multifd_compression_accel =
> +            params->multifd_compression_accel;
> +    }
>      if (params->has_xbzrle_cache_size) {
>          s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;
>          xbzrle_cache_resize(params->xbzrle_cache_size, errp);
> diff --git a/migration/options.h b/migration/options.h
> index 237f2d6b4a..e59bf4b5c1 100644
> --- a/migration/options.h
> +++ b/migration/options.h
> @@ -85,6 +85,7 @@ uint64_t migrate_avail_switchover_bandwidth(void);
>  uint64_t migrate_max_postcopy_bandwidth(void);
>  int migrate_multifd_channels(void);
>  MultiFDCompression migrate_multifd_compression(void);
> +MultiFDCompressionAccel migrate_multifd_compression_accel(void);
>  int migrate_multifd_zlib_level(void);
>  int migrate_multifd_zstd_level(void);
>  uint8_t migrate_throttle_trigger_threshold(void);
> diff --git a/qapi/migration.json b/qapi/migration.json
> index db3df12d6c..47239328e4 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -616,6 +616,22 @@
>              { 'name': 'zstd', 'if': 'CONFIG_ZSTD' } ] }
>
>  ##
> +# @MultiFDCompressionAccel:
> +#
> +# An enumeration of multifd compression accelerator.
> +#
> +# @auto: automatically determined if accelerator is available.

Well, it's always automatically determined.  Suggest:

   # @auto: if accelerators are available, enable one of them.

> +#
> +# @none: disable compression accelerator.
> +#
> +# @qpl: enable qpl compression accelerator.
> +#
> +# Since: 8.2
> +##
> +{ 'enum': 'MultiFDCompressionAccel',
> +  'data': [ 'auto', 'none',
> +            { 'name': 'qpl', 'if': 'CONFIG_QPL' } ] }
> +##
>  # @BitmapMigrationBitmapAliasTransform:
>  #
>  # @persistent: If present, the bitmap will be made persistent or
> @@ -798,6 +814,9 @@
>  # @multifd-compression: Which compression method to use.  Defaults to
>  #     none.  (Since 5.0)
>  #
> +# @multifd-compression-accel: Which compression accelerator to use.  Defaults to
> +#     auto.  (Since 8.2)

Long line.  Better:

   # @multifd-compression-accel: Which compression accelerator to use.
   #     Defaults to auto.  (Since 8.2)

> +#
>  # @multifd-zlib-level: Set the compression level to be used in live
>  #     migration, the compression level is an integer between 0 and 9,
>  #     where 0 means no compression, 1 means the best compression
> @@ -853,7 +872,7 @@
>             'block-incremental',
>             'multifd-channels',
>             'xbzrle-cache-size', 'max-postcopy-bandwidth',
> -           'max-cpu-throttle', 'multifd-compression',
> +           'max-cpu-throttle', 'multifd-compression', 'multifd-compression-accel',

Long line.  Either

              'max-cpu-throttle', 'multifd-compression',
              'multifd-compression-accel',

or, if you want to keep compression together

              'max-cpu-throttle',
              'multifd-compression', 'multifd-compression-accel',

or

              'max-cpu-throttle',
              'multifd-compression',
              'multifd-compression-accel',

You choose.

>             'multifd-zlib-level', 'multifd-zstd-level',
>             'block-bitmap-mapping',
>             { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] },
> @@ -974,6 +993,9 @@
>  # @multifd-compression: Which compression method to use.  Defaults to
>  #     none.  (Since 5.0)
>  #
> +# @multifd-compression-accel: Which compression acclerator to use.  Defaults to
> +#     auto.  (Since 8.2)
> +#
>  # @multifd-zlib-level: Set the compression level to be used in live
>  #     migration, the compression level is an integer between 0 and 9,
>  #     where 0 means no compression, 1 means the best compression
> @@ -1046,6 +1068,7 @@
>              '*max-postcopy-bandwidth': 'size',
>              '*max-cpu-throttle': 'uint8',
>              '*multifd-compression': 'MultiFDCompression',
> +            '*multifd-compression-accel': 'MultiFDCompressionAccel',
>              '*multifd-zlib-level': 'uint8',
>              '*multifd-zstd-level': 'uint8',
>              '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
> @@ -1257,6 +1280,7 @@

Missing documentation update.  Copy it from MigrateSetParameters,
please.

>              '*max-postcopy-bandwidth': 'size',
>              '*max-cpu-throttle': 'uint8',
>              '*multifd-compression': 'MultiFDCompression',
> +            '*multifd-compression-accel': 'MultiFDCompressionAccel',
>              '*multifd-zlib-level': 'uint8',
>              '*multifd-zstd-level': 'uint8',
>              '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
> --
> 2.39.3