From 7e2a037f3f349c21201152cecce32d8c8ff0bea0 Mon Sep 17 00:00:00 2001 From: Leonardo Bras Date: Mon, 20 Jun 2022 02:39:45 -0300 Subject: [PATCH 17/18] migration: Change zero_copy_send from migration parameter to migration capability MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Leonardo Brás RH-MergeRequest: 95: MSG_ZEROCOPY + Multifd RH-Commit: [11/11] e4a955607947896a49398ac8400241a0adac51a1 (LeoBras/centos-qemu-kvm) RH-Bugzilla: 1968509 RH-Acked-by: Miroslav Rezanina RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: Peter Xu When originally implemented, zero_copy_send was designed as a Migration paramenter. But taking into account how is that supposed to work, and how the difference between a capability and a parameter, it only makes sense that zero-copy-send would work better as a capability. Taking into account how recently the change got merged, it was decided that it's still time to make it right, and convert zero_copy_send into a Migration capability. Signed-off-by: Leonardo Bras Reviewed-by: Juan Quintela Acked-by: Markus Armbruster Acked-by: Peter Xu Signed-off-by: Juan Quintela Signed-off-by: Dr. David Alan Gilbert dgilbert: always define the capability, even on non-Linux but error if set; avoids build problems with the capability (cherry picked from commit 1abaec9a1b2c23f7aa94709a422128d9e42c3e0b) Signed-off-by: Leonardo Bras --- migration/migration.c | 58 +++++++++++++++++++------------------------ monitor/hmp-cmds.c | 6 ----- qapi/migration.json | 33 +++++++----------------- 3 files changed, 34 insertions(+), 63 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 102236fba0..2a141bfaf3 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -163,7 +163,8 @@ INITIALIZE_MIGRATE_CAPS_SET(check_caps_background_snapshot, MIGRATION_CAPABILITY_COMPRESS, MIGRATION_CAPABILITY_XBZRLE, MIGRATION_CAPABILITY_X_COLO, - MIGRATION_CAPABILITY_VALIDATE_UUID); + MIGRATION_CAPABILITY_VALIDATE_UUID, + MIGRATION_CAPABILITY_ZERO_COPY_SEND); /* When we add fault tolerance, we could have several migrations at once. For now we don't need to add @@ -899,10 +900,6 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) params->multifd_zlib_level = s->parameters.multifd_zlib_level; params->has_multifd_zstd_level = true; params->multifd_zstd_level = s->parameters.multifd_zstd_level; -#ifdef CONFIG_LINUX - params->has_zero_copy_send = true; - params->zero_copy_send = s->parameters.zero_copy_send; -#endif params->has_xbzrle_cache_size = true; params->xbzrle_cache_size = s->parameters.xbzrle_cache_size; params->has_max_postcopy_bandwidth = true; @@ -1263,6 +1260,24 @@ static bool migrate_caps_check(bool *cap_list, } } +#ifdef CONFIG_LINUX + if (cap_list[MIGRATION_CAPABILITY_ZERO_COPY_SEND] && + (!cap_list[MIGRATION_CAPABILITY_MULTIFD] || + migrate_use_compression() || + migrate_use_tls())) { + error_setg(errp, + "Zero copy only available for non-compressed non-TLS multifd migration"); + return false; + } +#else + if (cap_list[MIGRATION_CAPABILITY_ZERO_COPY_SEND]) { + error_setg(errp, + "Zero copy currently only available on Linux"); + return false; + } +#endif + + /* incoming side only */ if (runstate_check(RUN_STATE_INMIGRATE) && !migrate_multifd_is_allowed() && @@ -1485,16 +1500,6 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp) error_prepend(errp, "Invalid mapping given for block-bitmap-mapping: "); return false; } -#ifdef CONFIG_LINUX - if (params->zero_copy_send && - (!migrate_use_multifd() || - params->multifd_compression != MULTIFD_COMPRESSION_NONE || - (params->tls_creds && *params->tls_creds))) { - error_setg(errp, - "Zero copy only available for non-compressed non-TLS multifd migration"); - return false; - } -#endif return true; } @@ -1568,11 +1573,6 @@ static void migrate_params_test_apply(MigrateSetParameters *params, if (params->has_multifd_compression) { dest->multifd_compression = params->multifd_compression; } -#ifdef CONFIG_LINUX - if (params->has_zero_copy_send) { - dest->zero_copy_send = params->zero_copy_send; - } -#endif if (params->has_xbzrle_cache_size) { dest->xbzrle_cache_size = params->xbzrle_cache_size; } @@ -1685,11 +1685,6 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) if (params->has_multifd_compression) { s->parameters.multifd_compression = params->multifd_compression; } -#ifdef CONFIG_LINUX - if (params->has_zero_copy_send) { - s->parameters.zero_copy_send = params->zero_copy_send; - } -#endif if (params->has_xbzrle_cache_size) { s->parameters.xbzrle_cache_size = params->xbzrle_cache_size; xbzrle_cache_resize(params->xbzrle_cache_size, errp); @@ -2587,7 +2582,7 @@ bool migrate_use_zero_copy_send(void) s = migrate_get_current(); - return s->parameters.zero_copy_send; + return s->enabled_capabilities[MIGRATION_CAPABILITY_ZERO_COPY_SEND]; } #endif @@ -4243,10 +4238,6 @@ static Property migration_properties[] = { DEFINE_PROP_UINT8("multifd-zstd-level", MigrationState, parameters.multifd_zstd_level, DEFAULT_MIGRATE_MULTIFD_ZSTD_LEVEL), -#ifdef CONFIG_LINUX - DEFINE_PROP_BOOL("zero_copy_send", MigrationState, - parameters.zero_copy_send, false), -#endif DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState, parameters.xbzrle_cache_size, DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE), @@ -4284,6 +4275,10 @@ static Property migration_properties[] = { DEFINE_PROP_MIG_CAP("x-multifd", MIGRATION_CAPABILITY_MULTIFD), DEFINE_PROP_MIG_CAP("x-background-snapshot", MIGRATION_CAPABILITY_BACKGROUND_SNAPSHOT), +#ifdef CONFIG_LINUX + DEFINE_PROP_MIG_CAP("x-zero-copy-send", + MIGRATION_CAPABILITY_ZERO_COPY_SEND), +#endif DEFINE_PROP_END_OF_LIST(), }; @@ -4344,9 +4339,6 @@ static void migration_instance_init(Object *obj) params->has_multifd_compression = true; params->has_multifd_zlib_level = true; params->has_multifd_zstd_level = true; -#ifdef CONFIG_LINUX - params->has_zero_copy_send = true; -#endif params->has_xbzrle_cache_size = true; params->has_max_postcopy_bandwidth = true; params->has_max_cpu_throttle = true; diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index 55b48d3733..634968498b 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -1309,12 +1309,6 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) p->has_multifd_zstd_level = true; visit_type_uint8(v, param, &p->multifd_zstd_level, &err); break; -#ifdef CONFIG_LINUX - case MIGRATION_PARAMETER_ZERO_COPY_SEND: - p->has_zero_copy_send = true; - visit_type_bool(v, param, &p->zero_copy_send, &err); - break; -#endif case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE: p->has_xbzrle_cache_size = true; if (!visit_type_size(v, param, &cache_size, &err)) { diff --git a/qapi/migration.json b/qapi/migration.json index 4d833ecdd6..5105790cd0 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -463,6 +463,13 @@ # procedure starts. The VM RAM is saved with running VM. # (since 6.0) # +# @zero-copy-send: Controls behavior on sending memory pages on migration. +# When true, enables a zero-copy mechanism for sending +# memory pages, if host supports it. +# Requires that QEMU be permitted to use locked memory +# for guest RAM pages. +# (since 7.1) +# # Features: # @unstable: Members @x-colo and @x-ignore-shared are experimental. # @@ -476,7 +483,8 @@ 'block', 'return-path', 'pause-before-switchover', 'multifd', 'dirty-bitmaps', 'postcopy-blocktime', 'late-block-activate', { 'name': 'x-ignore-shared', 'features': [ 'unstable' ] }, - 'validate-uuid', 'background-snapshot'] } + 'validate-uuid', 'background-snapshot', + 'zero-copy-send'] } ## # @MigrationCapabilityStatus: @@ -741,12 +749,6 @@ # will consume more CPU. # Defaults to 1. (Since 5.0) # -# @zero-copy-send: Controls behavior on sending memory pages on migration. -# When true, enables a zero-copy mechanism for sending -# memory pages, if host supports it. -# Requires that QEMU be permitted to use locked memory -# for guest RAM pages. -# Defaults to false. (Since 7.1) # # @block-bitmap-mapping: Maps block nodes and bitmaps on them to # aliases for the purpose of dirty bitmap migration. Such @@ -787,7 +789,6 @@ 'xbzrle-cache-size', 'max-postcopy-bandwidth', 'max-cpu-throttle', 'multifd-compression', 'multifd-zlib-level' ,'multifd-zstd-level', - { 'name': 'zero-copy-send', 'if' : 'CONFIG_LINUX'}, 'block-bitmap-mapping' ] } ## @@ -914,13 +915,6 @@ # will consume more CPU. # Defaults to 1. (Since 5.0) # -# @zero-copy-send: Controls behavior on sending memory pages on migration. -# When true, enables a zero-copy mechanism for sending -# memory pages, if host supports it. -# Requires that QEMU be permitted to use locked memory -# for guest RAM pages. -# Defaults to false. (Since 7.1) -# # @block-bitmap-mapping: Maps block nodes and bitmaps on them to # aliases for the purpose of dirty bitmap migration. Such # aliases may for example be the corresponding names on the @@ -975,7 +969,6 @@ '*multifd-compression': 'MultiFDCompression', '*multifd-zlib-level': 'uint8', '*multifd-zstd-level': 'uint8', - '*zero-copy-send': { 'type': 'bool', 'if': 'CONFIG_LINUX' }, '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } } ## @@ -1122,13 +1115,6 @@ # will consume more CPU. # Defaults to 1. (Since 5.0) # -# @zero-copy-send: Controls behavior on sending memory pages on migration. -# When true, enables a zero-copy mechanism for sending -# memory pages, if host supports it. -# Requires that QEMU be permitted to use locked memory -# for guest RAM pages. -# Defaults to false. (Since 7.1) -# # @block-bitmap-mapping: Maps block nodes and bitmaps on them to # aliases for the purpose of dirty bitmap migration. Such # aliases may for example be the corresponding names on the @@ -1181,7 +1167,6 @@ '*multifd-compression': 'MultiFDCompression', '*multifd-zlib-level': 'uint8', '*multifd-zstd-level': 'uint8', - '*zero-copy-send': { 'type': 'bool', 'if': 'CONFIG_LINUX' }, '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } } ## -- 2.35.3