Add migrate-set-capabilities

The management can enable/disable a capability for the next migration by using
migrate-set-capabilities QMP command.
The user can use migrate_set_capability HMP command.

Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

hmp-commands.hx

@@ -858,6 +858,20 @@ STEXI
 @item migrate_set_downtime @var{second}
 @findex migrate_set_downtime
 Set maximum tolerated downtime (in seconds) for migration.
+ETEXI
+
+    {
+        .name       = "migrate_set_capability",
+        .args_type  = "capability:s,state:b",
+        .params     = "capability state",
+        .help       = "Enable/Disable the usage of a capability for migration",
+        .mhandler.cmd = hmp_migrate_set_capability,
+    },
+
+STEXI
+@item migrate_set_capability @var{capability} @var{state}
+@findex migrate_set_capability
+Enable/Disable the usage of a capability @var{capability} for migration.
 ETEXI
 
     {

hmp.c

@@ -770,6 +770,38 @@ void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict)
     qmp_migrate_set_speed(value, NULL);
 }
 
+void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict)
+{
+    const char *cap = qdict_get_str(qdict, "capability");
+    bool state = qdict_get_bool(qdict, "state");
+    Error *err = NULL;
+    MigrationCapabilityStatusList *caps = g_malloc0(sizeof(*caps));
+    int i;
+
+    for (i = 0; i < MIGRATION_CAPABILITY_MAX; i++) {
+        if (strcmp(cap, MigrationCapability_lookup[i]) == 0) {
+            caps->value = g_malloc0(sizeof(*caps->value));
+            caps->value->capability = i;
+            caps->value->state = state;
+            caps->next = NULL;
+            qmp_migrate_set_capabilities(caps, &err);
+            break;
+        }
+    }
+
+    if (i == MIGRATION_CAPABILITY_MAX) {
+        error_set(&err, QERR_INVALID_PARAMETER, cap);
+    }
+
+    qapi_free_MigrationCapabilityStatusList(caps);
+
+    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");

hmp.h

@@ -52,6 +52,7 @@ void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
 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_set_password(Monitor *mon, const QDict *qdict);
 void hmp_expire_password(Monitor *mon, const QDict *qdict);
 void hmp_eject(Monitor *mon, const QDict *qdict);

migration.c

@@ -190,6 +190,22 @@ MigrationInfo *qmp_query_migrate(Error **errp)
     return info;
 }
 
+void qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
+                                  Error **errp)
+{
+    MigrationState *s = migrate_get_current();
+    MigrationCapabilityStatusList *cap;
+
+    if (s->state == MIG_STATE_ACTIVE) {
+        error_set(errp, QERR_MIGRATION_ACTIVE);
+        return;
+    }
+
+    for (cap = params; cap; cap = cap->next) {
+        s->enabled_capabilities[cap->value->capability] = cap->value->state;
+    }
+}
+
 /* shared migration helpers */
 
 static int migrate_fd_cleanup(MigrationState *s)

qapi-schema.json

@@ -333,6 +333,18 @@
 { 'type': 'MigrationCapabilityStatus',
   'data': { 'capability' : 'MigrationCapability', 'state' : 'bool' } }
 
+##
+# @migrate-set-capabilities
+#
+# Enable/Disable the following migration capabilities (like xbzrle)
+#
+# @capabilities: json array of capability modifications to make
+#
+# Since: 1.2
+##
+{ 'command': 'migrate-set-capabilities',
+  'data': { 'capabilities': ['MigrationCapabilityStatus'] } }
+
 ##
 # @query-migrate-capabilities
 #

qmp-commands.hx

@@ -2143,6 +2143,29 @@ EQMP
     },
 
 SQMP
+migrate-set-capabilities
+-------
+
+Enable/Disable migration capabilities
+
+- "xbzrle": xbzrle support
+
+Arguments:
+
+Example:
+
+-> { "execute": "migrate-set-capabilities" , "arguments":
+     { "capabilities": [ { "capability": "xbzrle", "state": true } ] } }
+
+EQMP
+
+    {
+        .name       = "migrate-set-capabilities",
+        .args_type  = "capabilities:O",
+        .params     = "capability:s,state:b",
+	.mhandler.cmd_new = qmp_marshal_input_migrate_set_capabilities,
+    },
+SQMP
 query-migrate-capabilities
 -------