multifd: Add multifd-zlib-level parameter

This parameter specifies the zlib compression level. The next patch
will put it to use.

Signed-off-by: Juan Quintela <quintela@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

migration/migration.c

@@ -89,6 +89,8 @@
 #define DEFAULT_MIGRATE_X_CHECKPOINT_DELAY (200 * 100)
 #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2
 #define DEFAULT_MIGRATE_MULTIFD_COMPRESSION MULTIFD_COMPRESSION_NONE
+/* 0: means nocompress, 1: best speed, ... 9: best compress ratio */
+#define DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL 1
 
 /* Background transfer rate for postcopy, 0 means unlimited, note
  * that page requests can still exceed this limit.
@@ -801,6 +803,8 @@ 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_zlib_level = true;
+    params->multifd_zlib_level = s->parameters.multifd_zlib_level;
     params->has_xbzrle_cache_size = true;
     params->xbzrle_cache_size = s->parameters.xbzrle_cache_size;
     params->has_max_postcopy_bandwidth = true;
@@ -1208,6 +1212,13 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp)
         return false;
     }
 
+    if (params->has_multifd_zlib_level &&
+        (params->multifd_zlib_level > 9)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "multifd_zlib_level",
+                   "is invalid, it should be in the range of 0 to 9");
+        return false;
+    }
+
     if (params->has_xbzrle_cache_size &&
         (params->xbzrle_cache_size < qemu_target_page_size() ||
          !is_power_of_2(params->xbzrle_cache_size))) {
@@ -2254,6 +2265,15 @@ MultiFDCompression migrate_multifd_compression(void)
     return s->parameters.multifd_compression;
 }
 
+int migrate_multifd_zlib_level(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->parameters.multifd_zlib_level;
+}
+
 int migrate_use_xbzrle(void)
 {
     MigrationState *s;
@@ -3544,6 +3564,9 @@ static Property migration_properties[] = {
     DEFINE_PROP_MULTIFD_COMPRESSION("multifd-compression", MigrationState,
                       parameters.multifd_compression,
                       DEFAULT_MIGRATE_MULTIFD_COMPRESSION),
+    DEFINE_PROP_UINT8("multifd-zlib-level", MigrationState,
+                      parameters.multifd_zlib_level,
+                      DEFAULT_MIGRATE_MULTIFD_ZLIB_LEVEL),
     DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState,
                       parameters.xbzrle_cache_size,
                       DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE),
@@ -3635,6 +3658,7 @@ static void migration_instance_init(Object *obj)
     params->has_block_incremental = true;
     params->has_multifd_channels = true;
     params->has_multifd_compression = true;
+    params->has_multifd_zlib_level = true;
     params->has_xbzrle_cache_size = true;
     params->has_max_postcopy_bandwidth = true;
     params->has_max_cpu_throttle = true;

migration/migration.h

@@ -301,6 +301,7 @@ bool migrate_use_multifd(void);
 bool migrate_pause_before_switchover(void);
 int migrate_multifd_channels(void);
 MultiFDCompression migrate_multifd_compression(void);
+int migrate_multifd_zlib_level(void);
 
 int migrate_use_xbzrle(void);
 int64_t migrate_xbzrle_cache_size(void);

monitor/hmp-cmds.c

@@ -1837,6 +1837,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
         }
         p->multifd_compression = compress_type;
         break;
+    case MIGRATION_PARAMETER_MULTIFD_ZLIB_LEVEL:
+        p->has_multifd_zlib_level = true;
+        visit_type_int(v, param, &p->multifd_zlib_level, &err);
+        break;
     case MIGRATION_PARAMETER_XBZRLE_CACHE_SIZE:
         p->has_xbzrle_cache_size = true;
         visit_type_size(v, param, &cache_size, &err);

qapi/migration.json

@@ -602,6 +602,13 @@
 # @multifd-compression: Which compression method to use.
 #                       Defaults to none. (Since 5.0)
 #
+# @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 speed, and 9 means best compression ratio which
+#          will consume more CPU.
+#          Defaults to 1. (Since 5.0)
+#
 # Since: 2.4
 ##
 { 'enum': 'MigrationParameter',
@@ -614,7 +621,8 @@
            'downtime-limit', 'x-checkpoint-delay', 'block-incremental',
            'multifd-channels',
            'xbzrle-cache-size', 'max-postcopy-bandwidth',
-           'max-cpu-throttle', 'multifd-compression' ] }
+           'max-cpu-throttle', 'multifd-compression',
+           'multifd-zlib-level' ] }
 
 ##
 # @MigrateSetParameters:
@@ -707,6 +715,13 @@
 # @multifd-compression: Which compression method to use.
 #                       Defaults to none. (Since 5.0)
 #
+# @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 speed, and 9 means best compression ratio which
+#          will consume more CPU.
+#          Defaults to 1. (Since 5.0)
+#
 # Since: 2.4
 ##
 # TODO either fuse back into MigrationParameters, or make
@@ -733,7 +748,8 @@
             '*xbzrle-cache-size': 'size',
             '*max-postcopy-bandwidth': 'size',
             '*max-cpu-throttle': 'int',
-            '*multifd-compression': 'MultiFDCompression' } }
+            '*multifd-compression': 'MultiFDCompression',
+            '*multifd-zlib-level': 'int' } }
 
 ##
 # @migrate-set-parameters:
@@ -846,6 +862,13 @@
 # @multifd-compression: Which compression method to use.
 #                       Defaults to none. (Since 5.0)
 #
+# @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 speed, and 9 means best compression ratio which
+#          will consume more CPU.
+#          Defaults to 1. (Since 5.0)
+#
 # Since: 2.4
 ##
 { 'struct': 'MigrationParameters',
@@ -870,7 +893,8 @@
             '*xbzrle-cache-size': 'size',
             '*max-postcopy-bandwidth': 'size',
             '*max-cpu-throttle': 'uint8',
-            '*multifd-compression': 'MultiFDCompression' } }
+            '*multifd-compression': 'MultiFDCompression',
+            '*multifd-zlib-level': 'uint8' } }
 
 ##
 # @query-migrate-parameters: