The MigrationState is a QOM object with TYPE_DEVICE as a parent. This was done about eight years ago so the migration code could make use of qdev properties to define the defaults for the migration parameters and to be able to expose migration knobs for debugging via the '-global migration' command line option.
Due to unrelated historical reasons, three of the migration parameters (TLS options) received different types when used via the query-migrate-parameters QMP command than with the migrate-set-parameters command. This has created a lot of duplication in the migration code and in the QAPI documentation because the whole of MigrationParameters had to be duplicated as well. The migration code is now being fixed to remove the duplication and for that to happen the offending fields need to be reconciled into a single type. The StrOrNull type is going to be used. To keep the command line compatibility, the parameters need to continue being exposed via qdev properties accessible from the command line. Introduce a qdev property StrOrNull just for that. Note that this code is being kept in migration/options.c as this version of StrOrNull doesn't need to handle QNULL because it was never a valid option in the previous command line, which took a string. Signed-off-by: Fabiano Rosas <[email protected]> --- migration/options.c | 67 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff --git a/migration/options.c b/migration/options.c index e78324b80c..5f387437d1 100644 --- a/migration/options.c +++ b/migration/options.c @@ -83,6 +83,11 @@ #define DEFINE_PROP_MIG_CAP(name, x) \ DEFINE_PROP_BOOL(name, MigrationState, capabilities[x], false) +const PropertyInfo qdev_prop_StrOrNull; +#define DEFINE_PROP_STR_OR_NULL(_name, _state, _field) \ + DEFINE_PROP(_name, _state, _field, qdev_prop_StrOrNull, StrOrNull *, \ + .set_default = true) + #define DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT_PERIOD 1000 /* milliseconds */ #define DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT 1 /* MB/s */ @@ -206,6 +211,68 @@ const Property migration_properties[] = { }; const size_t migration_properties_count = ARRAY_SIZE(migration_properties); +static void get_StrOrNull(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + const Property *prop = opaque; + StrOrNull **ptr = object_field_prop_ptr(obj, prop); + StrOrNull *str_or_null = *ptr; + + if (!str_or_null) { + str_or_null = g_new0(StrOrNull, 1); + str_or_null->type = QTYPE_QSTRING; + str_or_null->u.s = g_strdup(""); + } else { + /* the setter doesn't allow QNULL */ + assert(str_or_null->type != QTYPE_QNULL); + } + visit_type_str(v, name, &str_or_null->u.s, errp); +} + +static void set_StrOrNull(Object *obj, Visitor *v, const char *name, + void *opaque, Error **errp) +{ + const Property *prop = opaque; + StrOrNull **ptr = object_field_prop_ptr(obj, prop); + StrOrNull *str_or_null = g_new0(StrOrNull, 1); + + /* + * Only str to keep compatibility, QNULL was never used via + * command line. + */ + str_or_null->type = QTYPE_QSTRING; + if (!visit_type_str(v, name, &str_or_null->u.s, errp)) { + return; + } + + qapi_free_StrOrNull(*ptr); + *ptr = str_or_null; +} + +static void release_StrOrNull(Object *obj, const char *name, void *opaque) +{ + const Property *prop = opaque; + qapi_free_StrOrNull(*(StrOrNull **)object_field_prop_ptr(obj, prop)); +} + +static void set_default_value_tls_opt(ObjectProperty *op, const Property *prop) +{ + object_property_set_default_str(op, ""); +} + +/* + * String property like qdev_prop_string, except it's backed by a + * StrOrNull instead of a char *. This is intended for + * TYPE_MIGRATION's TLS options. + */ +const PropertyInfo qdev_prop_StrOrNull = { + .type = "StrOrNull", + .get = get_StrOrNull, + .set = set_StrOrNull, + .release = release_StrOrNull, + .set_default_value = set_default_value_tls_opt, +}; + bool migrate_auto_converge(void) { MigrationState *s = migrate_get_current(); -- 2.51.0
