Add property that allows zerocopy migration of memory pages,
and also includes a helper function migrate_use_zerocopy() to check
if it's enabled.
No code is introduced to actually do the migration, but it allow
future implementations to enable/disable this feature.
On non-Linux builds this parameter is compiled-out.
Signed-off-by: Leonardo Bras <leob...@redhat.com>
---
qapi/migration.json | 18 ++++++++++++++++++
migration/migration.h | 5 +++++
migration/migration.c | 32 ++++++++++++++++++++++++++++++++
migration/multifd.c | 17 +++++++++--------
migration/socket.c | 5 +++++
monitor/hmp-cmds.c | 6 ++++++
6 files changed, 75 insertions(+), 8 deletions(-)
diff --git a/qapi/migration.json b/qapi/migration.json
index bbfd48cf0b..9534c299d7 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -730,6 +730,11 @@
# will consume more CPU.
# Defaults to 1. (Since 5.0)
#
+# @zerocopy: Controls behavior on sending memory pages on migration.
+# When true, enables a zerocopy mechanism for sending memory
+# pages, if host supports it.
+# Defaults to false. (Since 6.2)
+#
# @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
@@ -769,6 +774,7 @@
'xbzrle-cache-size', 'max-postcopy-bandwidth',
'max-cpu-throttle', 'multifd-compression',
'multifd-zlib-level' ,'multifd-zstd-level',
+ { 'name': 'zerocopy', 'if' : 'CONFIG_LINUX'},
'block-bitmap-mapping' ] }
##
@@ -895,6 +901,11 @@
# will consume more CPU.
# Defaults to 1. (Since 5.0)
#
+# @zerocopy: Controls behavior on sending memory pages on migration.
+# When true, enables a zerocopy mechanism for sending memory
+# pages, if host supports it.
+# Defaults to false. (Since 6.2)
+#
# @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
@@ -949,6 +960,7 @@
'*multifd-compression': 'MultiFDCompression',
'*multifd-zlib-level': 'uint8',
'*multifd-zstd-level': 'uint8',
+ '*zerocopy': { 'type': 'bool', 'if': 'CONFIG_LINUX' },
'*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
##
@@ -1095,6 +1107,11 @@
# will consume more CPU.
# Defaults to 1. (Since 5.0)
#
+# @zerocopy: Controls behavior on sending memory pages on migration.
+# When true, enables a zerocopy mechanism for sending memory
+# pages, if host supports it.
+# Defaults to false. (Since 6.2)
+#
# @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
@@ -1147,6 +1164,7 @@
'*multifd-compression': 'MultiFDCompression',
'*multifd-zlib-level': 'uint8',
'*multifd-zstd-level': 'uint8',
+ '*zerocopy': { 'type': 'bool', 'if': 'CONFIG_LINUX' },
'*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
##
diff --git a/migration/migration.h b/migration/migration.h
index 8130b703eb..e61ef81f26 100644
--- a/migration/migration.h
+++ b/migration/migration.h
@@ -339,6 +339,11 @@ MultiFDCompression migrate_multifd_compression(void);
int migrate_multifd_zlib_level(void);
int migrate_multifd_zstd_level(void);
+#ifdef CONFIG_LINUX
+int migrate_use_zerocopy(void);
+#else
+#define migrate_use_zerocopy() (0)
+#endif
int migrate_use_xbzrle(void);
uint64_t migrate_xbzrle_cache_size(void);
bool migrate_colo_enabled(void);
diff --git a/migration/migration.c b/migration/migration.c
index abaf6f9e3d..add3dabc56 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -886,6 +886,10 @@ 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_zerocopy = true;
+ params->zerocopy = s->parameters.zerocopy;
+#endif
params->has_xbzrle_cache_size = true;
params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;
params->has_max_postcopy_bandwidth = true;
@@ -1538,6 +1542,11 @@ 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_zerocopy) {
+ dest->zerocopy = params->zerocopy;
+ }
+#endif
if (params->has_xbzrle_cache_size) {
dest->xbzrle_cache_size = params->xbzrle_cache_size;
}
@@ -1650,6 +1659,11 @@ 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_zerocopy) {
+ s->parameters.zerocopy = params->zerocopy;
+ }
+#endif
if (params->has_xbzrle_cache_size) {
s->parameters.xbzrle_cache_size = params->xbzrle_cache_size;
xbzrle_cache_resize(params->xbzrle_cache_size, errp);
@@ -2540,6 +2554,17 @@ int migrate_multifd_zstd_level(void)
return s->parameters.multifd_zstd_level;
}
+#ifdef CONFIG_LINUX
+int migrate_use_zerocopy(void)
+{
+ MigrationState *s;
+
+ s = migrate_get_current();
+
+ return s->parameters.zerocopy;
+}
+#endif
+
int migrate_use_xbzrle(void)
{
MigrationState *s;
@@ -4190,6 +4215,10 @@ 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("zerocopy", MigrationState,
+ parameters.zerocopy, false),
+#endif
DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState,
parameters.xbzrle_cache_size,
DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE),
@@ -4287,6 +4316,9 @@ 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_zerocopy = true;
+#endif
params->has_xbzrle_cache_size = true;
params->has_max_postcopy_bandwidth = true;
params->has_max_cpu_throttle = true;
diff --git a/migration/multifd.c b/migration/multifd.c
index 7c9deb1921..ab8f0f97be 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -854,16 +854,17 @@ static void multifd_new_send_channel_async(QIOTask *task,
gpointer opaque)
trace_multifd_new_send_channel_async(p->id);
if (qio_task_propagate_error(task, &local_err)) {
goto cleanup;
- } else {
- p->c = QIO_CHANNEL(sioc);
- qio_channel_set_delay(p->c, false);
- p->running = true;
- if (!multifd_channel_connect(p, sioc, local_err)) {
- goto cleanup;
- }
- return;
}
+ p->c = QIO_CHANNEL(sioc);
+ qio_channel_set_delay(p->c, false);
+ p->running = true;
+ if (!multifd_channel_connect(p, sioc, local_err)) {
+ goto cleanup;
+ }
+
+ return;
+
cleanup:
multifd_new_send_channel_cleanup(p, sioc, local_err);
}
diff --git a/migration/socket.c b/migration/socket.c
index 05705a32d8..e26e94aa0c 100644
--- a/migration/socket.c
+++ b/migration/socket.c
@@ -77,6 +77,11 @@ static void socket_outgoing_migration(QIOTask *task,
} else {
trace_migration_socket_outgoing_connected(data->hostname);
}
+
+ if (migrate_use_zerocopy()) {
+ error_setg(&err, "Zerocopy not available in migration");
+ }
+
migration_channel_connect(data->s, sioc, data->hostname, err);
object_unref(OBJECT(sioc));
}
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 9c91bf93e9..442679dcfa 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -1297,6 +1297,12 @@ 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_ZEROCOPY:
+ p->has_zerocopy = true;
+ visit_type_bool(v, param, &p->zerocopy, &err);
+ break;
+#endif
case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE:
p->has_xbzrle_cache_size = true;
if (!visit_type_size(v, param, &cache_size, &err)) {
--
2.33.1
