> -----Original Message-----
> From: Markus Armbruster <arm...@redhat.com>
> Sent: Friday, December 1, 2023 5:17 PM
> To: Liu, Yuan1 <yuan1....@intel.com>
> Cc: quint...@redhat.com; pet...@redhat.com; faro...@suse.de;
> leob...@redhat.com; qemu-devel@nongnu.org; Zou, Nanhai
> <nanhai....@intel.com>
> Subject: Re: [PATCH v2 1/4] migration: Introduce multifd-compression-accel
> parameter
>
> Yuan Liu <yuan1....@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....@intel.com>
> > Reviewed-by: Nanhai Zou <nanhai....@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.
Sure, I will update a document and all the above suggestions in the next version
