[Qemu-devel] [v5 12/12] migration: Add commands to set and query parameter

[Liang Li]

Add the qmp and hmp commands to tune and query the parameters used in
live migration.

Signed-off-by: Liang Li <address@hidden>
Signed-off-by: Yang Zhang <address@hidden>
---
 hmp-commands.hx               | 17 ++++++++
 hmp.c                         | 56 +++++++++++++++++++++++++
 hmp.h                         |  4 ++
 include/migration/migration.h |  4 +-
 migration/migration.c         | 96 +++++++++++++++++++++++++++++++++++++------
 monitor.c                     | 25 +++++++++++
 qapi-schema.json              | 86 ++++++++++++++++++++++++++++++++++++++
 qmp-commands.hx               | 66 +++++++++++++++++++++++++++++
 8 files changed, 339 insertions(+), 15 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index e37bc8b..ed0c06a 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -985,6 +985,21 @@ Enable/Disable the usage of a capability @var{capability} 
for migration.
 ETEXI
 
     {
+        .name       = "migrate_set_parameter",
+        .args_type  = "parameter:s,value:i",
+        .params     = "parameter value",
+        .help       = "Set the parameter for migration",
+        .mhandler.cmd = hmp_migrate_set_parameter,
+        .command_completion = migrate_set_parameter_completion,
+    },
+
+STEXI
address@hidden migrate_set_parameter @var{parameter} @var{value}
address@hidden migrate_set_parameter
+Set the parameter @var{parameter} for migration.
+ETEXI
+
+    {
         .name       = "client_migrate_info",
         .args_type  = 
"protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
         .params     = "protocol hostname port tls-port cert-subject",
@@ -1764,6 +1779,8 @@ show user network stack connection states
 show migration status
 @item info migrate_capabilities
 show current migration capabilities
address@hidden info migrate_parameters
+show current migration parameters
 @item info migrate_cache_size
 show current migration XBZRLE cache size
 @item info balloon
diff --git a/hmp.c b/hmp.c
index b47f331..1f67651 100644
--- a/hmp.c
+++ b/hmp.c
@@ -246,6 +246,27 @@ void hmp_info_migrate_capabilities(Monitor *mon, const 
QDict *qdict)
     qapi_free_MigrationCapabilityStatusList(caps);
 }
 
+void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
+{
+    MigrationParameterStatusList *params, *p;
+    MigrationParameterInt *data;
+
+    params = qmp_query_migrate_parameters(NULL);
+
+    if (params) {
+        monitor_printf(mon, "parameters:");
+        for (p = params; p; p = p->next) {
+            data = (MigrationParameterInt *)p->value->data;
+            monitor_printf(mon, " %s: %" PRId64,
+                           MigrationParameter_lookup[p->value->kind],
+                           data->value);
+        }
+        monitor_printf(mon, "\n");
+    }
+
+    qapi_free_MigrationParameterStatusList(params);
+}
+
 void hmp_info_migrate_cache_size(Monitor *mon, const QDict *qdict)
 {
     monitor_printf(mon, "xbzrel cache size: %" PRId64 " kbytes\n",
@@ -1140,6 +1161,41 @@ void hmp_migrate_set_capability(Monitor *mon, const 
QDict *qdict)
     }
 }
 
+void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
+{
+    const char *param = qdict_get_str(qdict, "parameter");
+    int value = qdict_get_int(qdict, "value");
+    Error *err = NULL;
+    MigrationParameterStatusList *params = g_malloc0(sizeof(*params));
+    MigrationParameterInt *data;
+    int i;
+
+    for (i = 0; i < MIGRATION_PARAMETER_MAX; i++) {
+        if (strcmp(param, MigrationParameter_lookup[i]) == 0) {
+            params->value = g_malloc0(sizeof(*params->value));
+            params->value->kind = i;
+            params->value->data = g_malloc0(sizeof(MigrationParameterInt));
+            data = (MigrationParameterInt *)params->value->data;
+            data->value = value;
+            params->next = NULL;
+            qmp_migrate_set_parameters(params, &err);
+            break;
+        }
+    }
+
+    if (i == MIGRATION_PARAMETER_MAX) {
+        error_set(&err, QERR_INVALID_PARAMETER, param);
+    }
+
+    qapi_free_MigrationParameterStatusList(params);
+
+    if (err) {
+        monitor_printf(mon, "migrate_set_parameter: %s\n",
+                       error_get_pretty(err));
+        error_free(err);
+    }
+}
+
 void hmp_set_password(Monitor *mon, const QDict *qdict)
 {
     const char *protocol  = qdict_get_str(qdict, "protocol");
diff --git a/hmp.h b/hmp.h
index 4bb5dca..b2b2d2c 100644
--- a/hmp.h
+++ b/hmp.h
@@ -28,6 +28,7 @@ void hmp_info_chardev(Monitor *mon, const QDict *qdict);
 void hmp_info_mice(Monitor *mon, const QDict *qdict);
 void hmp_info_migrate(Monitor *mon, const QDict *qdict);
 void hmp_info_migrate_capabilities(Monitor *mon, const QDict *qdict);
+void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict);
 void hmp_info_migrate_cache_size(Monitor *mon, const QDict *qdict);
 void hmp_info_cpus(Monitor *mon, const QDict *qdict);
 void hmp_info_block(Monitor *mon, const QDict *qdict);
@@ -63,6 +64,7 @@ void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict);
 void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict);
 void hmp_set_password(Monitor *mon, const QDict *qdict);
 void hmp_expire_password(Monitor *mon, const QDict *qdict);
@@ -111,6 +113,8 @@ void watchdog_action_completion(ReadLineState *rs, int 
nb_args,
                                 const char *str);
 void migrate_set_capability_completion(ReadLineState *rs, int nb_args,
                                        const char *str);
+void migrate_set_parameter_completion(ReadLineState *rs, int nb_args,
+                                      const char *str);
 void host_net_add_completion(ReadLineState *rs, int nb_args, const char *str);
 void host_net_remove_completion(ReadLineState *rs, int nb_args,
                                 const char *str);
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 9ac1b23..434cc96 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -51,9 +51,7 @@ struct MigrationState
     QEMUBH *cleanup_bh;
     QEMUFile *file;
     QemuThread *compress_thread;
-    int compress_thread_count;
-    int decompress_thread_count;
-    int compress_level;
+    int parameters[MIGRATION_PARAMETER_MAX];
 
     int state;
     MigrationParams params;
diff --git a/migration/migration.c b/migration/migration.c
index 55f749e..89750ba 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -66,9 +66,12 @@ MigrationState *migrate_get_current(void)
         .bandwidth_limit = MAX_THROTTLE,
         .xbzrle_cache_size = DEFAULT_MIGRATE_CACHE_SIZE,
         .mbps = -1,
-        .compress_thread_count = DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT,
-        .decompress_thread_count = DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
-        .compress_level = DEFAULT_MIGRATE_COMPRESS_LEVEL,
+        .parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] =
+                DEFAULT_MIGRATE_COMPRESS_LEVEL,
+        .parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
+                DEFAULT_MIGRATE_COMPRESS_THREAD_COUNT,
+        .parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
+                DEFAULT_MIGRATE_DECOMPRESS_THREAD_COUNT,
     };
 
     return &current_migration;
@@ -178,6 +181,33 @@ MigrationCapabilityStatusList 
*qmp_query_migrate_capabilities(Error **errp)
     return head;
 }
 
+MigrationParameterStatusList *qmp_query_migrate_parameters(Error **errp)
+{
+    MigrationParameterStatusList *head = NULL;
+    MigrationParameterStatusList *params;
+    MigrationState *s = migrate_get_current();
+    MigrationParameterInt *data;
+    int i;
+
+    params = NULL; /* silence compiler warning */
+    for (i = 0; i < MIGRATION_PARAMETER_MAX; i++) {
+        if (head == NULL) {
+            head = g_malloc0(sizeof(*params));
+            params = head;
+        } else {
+            params->next = g_malloc0(sizeof(*params));
+            params = params->next;
+        }
+        params->value = g_malloc(sizeof(*params->value));
+        params->value->kind = i;
+        params->value->data = g_malloc(sizeof(MigrationParameterInt));
+        data = (MigrationParameterInt *)params->value->data;
+        data->value = s->parameters[i];
+    }
+
+    return head;
+}
+
 static void get_xbzrle_cache_stats(MigrationInfo *info)
 {
     if (migrate_use_xbzrle()) {
@@ -294,6 +324,44 @@ void 
qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
     }
 }
 
+void qmp_migrate_set_parameters(MigrationParameterStatusList *params,
+                                Error **errp)
+{
+    MigrationState *s = migrate_get_current();
+    MigrationParameterStatusList *p;
+    MigrationParameterInt *data;
+
+    for (p = params; p; p = p->next) {
+        switch (p->value->kind) {
+        case MIGRATION_PARAMETER_COMPRESS_LEVEL:
+            data = (MigrationParameterInt *)p->value->data;
+            if (data->value < 0 || data->value > 9) {
+                error_set(errp, QERR_INVALID_PARAMETER_VALUE, "compress_level",
+                          "is invalid, it should be in the range of 0 to 9");
+                return;
+            }
+            break;
+        case MIGRATION_PARAMETER_COMPRESS_THREADS:
+        case MIGRATION_PARAMETER_DECOMPRESS_THREADS:
+            if (s->state == MIG_STATE_ACTIVE || s->state == MIG_STATE_SETUP) {
+                error_set(errp, QERR_MIGRATION_ACTIVE);
+                return;
+            }
+            data = (MigrationParameterInt *)p->value->data;
+            if (data->value < 1 || data->value > 255) {
+                error_set(errp, QERR_INVALID_PARAMETER_VALUE,
+                          "(de)compress_threads",
+                          "is invalid, it should be in the range of 1 to 255");
+                return;
+            }
+            break;
+        default:
+           return;
+        }
+        s->parameters[p->value->kind] = data->value;
+    }
+}
+
 /* shared migration helpers */
 
 static void migrate_set_state(MigrationState *s, int old_state, int new_state)
@@ -400,9 +468,11 @@ static MigrationState *migrate_init(const MigrationParams 
*params)
     int64_t bandwidth_limit = s->bandwidth_limit;
     bool enabled_capabilities[MIGRATION_CAPABILITY_MAX];
     int64_t xbzrle_cache_size = s->xbzrle_cache_size;
-    int compress_level = s->compress_level;
-    int compress_thread_count = s->compress_thread_count;
-    int decompress_thread_count = s->decompress_thread_count;
+    int compress_level = s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
+    int compress_thread_count =
+            s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
+    int decompress_thread_count =
+            s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
 
     memcpy(enabled_capabilities, s->enabled_capabilities,
            sizeof(enabled_capabilities));
@@ -413,9 +483,11 @@ static MigrationState *migrate_init(const MigrationParams 
*params)
            sizeof(enabled_capabilities));
     s->xbzrle_cache_size = xbzrle_cache_size;
 
-    s->compress_level = compress_level;
-    s->compress_thread_count = compress_thread_count;
-    s->decompress_thread_count = decompress_thread_count;
+    s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
+    s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS] =
+               compress_thread_count;
+    s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS] =
+               decompress_thread_count;
     s->bandwidth_limit = bandwidth_limit;
     s->state = MIG_STATE_SETUP;
     trace_migrate_set_state(MIG_STATE_SETUP);
@@ -603,7 +675,7 @@ int migrate_compress_level(void)
 
     s = migrate_get_current();
 
-    return s->compress_level;
+    return s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL];
 }
 
 int migrate_compress_threads(void)
@@ -612,7 +684,7 @@ int migrate_compress_threads(void)
 
     s = migrate_get_current();
 
-    return s->compress_thread_count;
+    return s->parameters[MIGRATION_PARAMETER_COMPRESS_THREADS];
 }
 
 int migrate_decompress_threads(void)
@@ -621,7 +693,7 @@ int migrate_decompress_threads(void)
 
     s = migrate_get_current();
 
-    return s->decompress_thread_count;
+    return s->parameters[MIGRATION_PARAMETER_DECOMPRESS_THREADS];
 }
 
 int migrate_use_xbzrle(void)
diff --git a/monitor.c b/monitor.c
index c3cc060..499ae1c 100644
--- a/monitor.c
+++ b/monitor.c
@@ -2873,6 +2873,13 @@ static mon_cmd_t info_cmds[] = {
         .mhandler.cmd = hmp_info_migrate_capabilities,
     },
     {
+        .name       = "migrate_parameters",
+        .args_type  = "",
+        .params     = "",
+        .help       = "show current migration parameters",
+        .mhandler.cmd = hmp_info_migrate_parameters,
+    },
+    {
         .name       = "migrate_cache_size",
         .args_type  = "",
         .params     = "",
@@ -4555,6 +4562,24 @@ void migrate_set_capability_completion(ReadLineState 
*rs, int nb_args,
     }
 }
 
+void migrate_set_parameter_completion(ReadLineState *rs, int nb_args,
+                                      const char *str)
+{
+    size_t len;
+
+    len = strlen(str);
+    readline_set_completion_index(rs, len);
+    if (nb_args == 2) {
+        int i;
+        for (i = 0; i < MIGRATION_PARAMETER_MAX; i++) {
+            const char *name = MigrationParameter_lookup[i];
+            if (!strncmp(str, name, len)) {
+                readline_add_completion(rs, name);
+            }
+        }
+    }
+}
+
 void host_net_add_completion(ReadLineState *rs, int nb_args, const char *str)
 {
     int i;
diff --git a/qapi-schema.json b/qapi-schema.json
index 0dfc4ce..5bf21fe 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -541,6 +541,92 @@
 ##
 { 'command': 'query-migrate-capabilities', 'returns':   
['MigrationCapabilityStatus']}
 
+# @MigrationParameter
+#
+# Migration parameters enumeration
+#
+# @compress-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.
+#
+# @compress-threads: Set compression thread count to be used in live migration,
+#          the compression thread count is an integer between 1 and 255.
+#
+# @decompress-threads: Set decompression thread count to be used in live
+#          migration, the decompression thread count is an integer between 1
+#          and 255. Usually, decompression is at least 4 times as fast as
+#          compression, so set the decompress-threads to the number about 1/4
+#          of compress-threads is adequate.
+#
+# Since: 2.3
+##
+{ 'enum': 'MigrationParameter',
+  'data': ['compress-level', 'compress-threads', 'decompress-threads'] }
+##
+# @MigrationParameterBase
+#
+# Migration parameter information
+#
+# @parameter: the parameter of migration
+#
+# Since: 2.3
+##
+{ 'type': 'MigrationParameterBase',
+  'data': {'parameter': 'MigrationParameter'} }
+##
+# @MigrationParameterInt
+#
+# Migration parameter information
+#
+# @value: parameter int
+#
+# Since: 2.3
+##
+{ 'type': 'MigrationParameterInt',
+  'data': {'value': 'int'} }
+##
+# @MigrationParameterStatus
+#
+# Migration parameter information
+#
+# @compress-level: compression level
+#
+# @compress-threads: compression thread count
+#
+# @decompress-threads: decompression thread count
+#
+# Since: 2.3
+##
+{ 'union': 'MigrationParameterStatus',
+  'base': 'MigrationParameterBase',
+  'discriminator': 'parameter',
+  'data': { 'compress-level': 'MigrationParameterInt',
+            'compress-threads': 'MigrationParameterInt',
+            'decompress-threads': 'MigrationParameterInt'} }
+#
+# @migrate-set-parameters
+#
+# Set the following migration parameters (like compress-level)
+#
+# @parameters: json array of parameter modifications to make
+#
+# Since: 2.3
+##
+{ 'command': 'migrate-set-parameters',
+  'data': { 'parameters': ['MigrationParameterStatus'] } }
+##
+# @query-migrate-parameters
+#
+# Returns information about the current migration parameters status
+#
+# Returns: @MigrationParametersStatus
+#
+# Since: 2.3
+##
+{ 'command': 'query-migrate-parameters',
+  'returns': ['MigrationParameterStatus'] }
+##
 ##
 # @MouseInfo:
 #
diff --git a/qmp-commands.hx b/qmp-commands.hx
index a85d847..2c4737b 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -3295,6 +3295,72 @@ EQMP
     },
 
 SQMP
+migrate-set-parameters
+----------------------
+
+Set migration parameters
+
+- "compress-level": set compression level during migration
+- "compress-threads": set compression thread count for migration
+- "decompress-threads": set decompression thread count for migration
+
+Arguments:
+
+Example:
+
+-> { "execute": "migrate-set-parameters" , "arguments":
+     { "parameters": [ { "parameter": "compress-level", "value": 1 } ] } }
+
+EQMP
+
+    {
+        .name       = "migrate-set-parameters",
+        .args_type  = "parameters:O",
+        .params     = "parameter:s,value:O",
+       .mhandler.cmd_new = qmp_marshal_input_migrate_set_parameters,
+    },
+SQMP
+query-migrate-parameters
+------------------------
+
+Query current migration parameters
+
+- "parameters": migration parameters value
+         - "compress-level" : compression level value (json-int)
+         - "compress-threads" : compression thread count value (json-int)
+         - "decompress-threads" : decompression thread count value (json-int)
+
+Arguments:
+
+Example:
+
+-> { "execute": "query-migrate-parameters" }
+<- {
+      "return": [
+         {
+            "parameter": "compress-level",
+            "value": 1
+         },
+         {
+            "parameter": "compress-threads",
+            "value": 8
+         },
+         {
+            "parameter": "decompress-threads",
+            "value": 2
+         }
+      ]
+   }
+
+EQMP
+
+    {
+        .name       = "query-migrate-parameters",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_input_query_migrate_parameters,
+    },
+
+SQMP
 query-balloon
 -------------
 
-- 
1.9.1