migration: cpr-exec-command parameter

Create the cpr-exec-command migration parameter, defined as a list of
strings.  It will be used for cpr-exec migration mode in a subsequent
patch, and contains forward references to cpr-exec mode in the qapi
doc.

No functional change, except that cpr-exec-command is shown by the
'info migrate' command.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Link: https://lore.kernel.org/r/1759332851-370353-5-git-send-email-steven.sistare@oracle.com
Signed-off-by: Peter Xu <peterx@redhat.com>

hmp-commands.hx

@@ -1009,7 +1009,7 @@ ERST
 
     {
         .name       = "migrate_set_parameter",
-        .args_type  = "parameter:s,value:s",
+        .args_type  = "parameter:s,value:S",
         .params     = "parameter value",
         .help       = "Set the parameter for migration",
         .cmd        = hmp_migrate_set_parameter,

migration/migration-hmp-cmds.c

@@ -306,6 +306,18 @@ void hmp_info_migrate_capabilities(Monitor *mon, const QDict *qdict)
     qapi_free_MigrationCapabilityStatusList(caps);
 }
 
+static void monitor_print_cpr_exec_command(Monitor *mon, strList *args)
+{
+    monitor_printf(mon, "%s:",
+        MigrationParameter_str(MIGRATION_PARAMETER_CPR_EXEC_COMMAND));
+
+    while (args) {
+        monitor_printf(mon, " %s", args->value);
+        args = args->next;
+    }
+    monitor_printf(mon, "\n");
+}
+
 void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
 {
     MigrationParameters *params;
@@ -437,6 +449,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
                                MIGRATION_PARAMETER_DIRECT_IO),
                            params->direct_io ? "on" : "off");
         }
+
+        assert(params->has_cpr_exec_command);
+        monitor_print_cpr_exec_command(mon, params->cpr_exec_command);
     }
 
     qapi_free_MigrationParameters(params);
@@ -718,6 +733,21 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
         p->has_direct_io = true;
         visit_type_bool(v, param, &p->direct_io, &err);
         break;
+    case MIGRATION_PARAMETER_CPR_EXEC_COMMAND: {
+        g_autofree char **strv = NULL;
+        g_autoptr(GError) gerr = NULL;
+        strList **tail = &p->cpr_exec_command;
+
+        if (!g_shell_parse_argv(valuestr, NULL, &strv, &gerr)) {
+            error_setg(&err, "%s", gerr->message);
+            break;
+        }
+        for (int i = 0; strv[i]; i++) {
+            QAPI_LIST_APPEND(tail, strv[i]);
+        }
+        p->has_cpr_exec_command = true;
+        break;
+    }
     default:
         g_assert_not_reached();
     }

migration/options.c

@@ -959,6 +959,9 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
     params->zero_page_detection = s->parameters.zero_page_detection;
     params->has_direct_io = true;
     params->direct_io = s->parameters.direct_io;
+    params->has_cpr_exec_command = true;
+    params->cpr_exec_command = QAPI_CLONE(strList,
+                                          s->parameters.cpr_exec_command);
 
     return params;
 }
@@ -993,6 +996,7 @@ void migrate_params_init(MigrationParameters *params)
     params->has_mode = true;
     params->has_zero_page_detection = true;
     params->has_direct_io = true;
+    params->has_cpr_exec_command = true;
 }
 
 /*
@@ -1297,6 +1301,10 @@ static void migrate_params_test_apply(MigrateSetParameters *params,
     if (params->has_direct_io) {
         dest->direct_io = params->direct_io;
     }
+
+    if (params->has_cpr_exec_command) {
+        dest->cpr_exec_command = params->cpr_exec_command;
+    }
 }
 
 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1429,6 +1437,12 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
     if (params->has_direct_io) {
         s->parameters.direct_io = params->direct_io;
     }
+
+    if (params->has_cpr_exec_command) {
+        qapi_free_strList(s->parameters.cpr_exec_command);
+        s->parameters.cpr_exec_command =
+            QAPI_CLONE(strList, params->cpr_exec_command);
+    }
 }
 
 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)

qapi/migration.json

@@ -924,6 +924,10 @@
 #     only has effect if the @mapped-ram capability is enabled.
 #     (Since 9.1)
 #
+# @cpr-exec-command: Command to start the new QEMU process when @mode
+#     is @cpr-exec.  The first list element is the program's filename,
+#     the remainder its arguments.  (Since 10.2)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and
@@ -950,7 +954,8 @@
            'vcpu-dirty-limit',
            'mode',
            'zero-page-detection',
-           'direct-io'] }
+           'direct-io',
+           'cpr-exec-command'] }
 
 ##
 # @MigrateSetParameters:
@@ -1105,6 +1110,10 @@
 #     only has effect if the @mapped-ram capability is enabled.
 #     (Since 9.1)
 #
+# @cpr-exec-command: Command to start the new QEMU process when @mode
+#     is @cpr-exec.  The first list element is the program's filename,
+#     the remainder its arguments.  (Since 10.2)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and
@@ -1146,7 +1155,8 @@
             '*vcpu-dirty-limit': 'uint64',
             '*mode': 'MigMode',
             '*zero-page-detection': 'ZeroPageDetection',
-            '*direct-io': 'bool' } }
+            '*direct-io': 'bool',
+            '*cpr-exec-command': [ 'str' ]} }
 
 ##
 # @migrate-set-parameters:
@@ -1315,6 +1325,10 @@
 #     only has effect if the @mapped-ram capability is enabled.
 #     (Since 9.1)
 #
+# @cpr-exec-command: Command to start the new QEMU process when @mode
+#     is @cpr-exec.  The first list element is the program's filename,
+#     the remainder its arguments.  (Since 10.2)
+#
 # Features:
 #
 # @unstable: Members @x-checkpoint-delay and
@@ -1353,7 +1367,8 @@
             '*vcpu-dirty-limit': 'uint64',
             '*mode': 'MigMode',
             '*zero-page-detection': 'ZeroPageDetection',
-            '*direct-io': 'bool' } }
+            '*direct-io': 'bool',
+            '*cpr-exec-command': [ 'str' ]} }
 
 ##
 # @query-migrate-parameters: