On Wed, Sep 02, 2026 at 07:15:38PM -0300, Fabiano Rosas wrote:
> There are a couple of situations where all fields of a
> MigrationParameters object need to be marked as present: when cloning
> an entire object and when creating the transient object in
> qmp_query_migrate(). The query-migrate-parameters QMP command contract
> requires that all parameters, except block-bitmap-mapping, are present
> in the output.
>
> Validate that a given object has all has_* fields set to true.
>
> Signed-off-by: Fabiano Rosas <[email protected]>
> ---
> migration/options.c | 54 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 54 insertions(+)
>
> diff --git a/migration/options.c b/migration/options.c
> index bd7be8f9832..5d17acdd881 100644
> --- a/migration/options.c
> +++ b/migration/options.c
> @@ -12,6 +12,7 @@
> */
>
> #include "qemu/osdep.h"
> +#include "qemu/cutils.h"
> #include "qemu/error-report.h"
> #include "qemu/units.h"
> #include "exec/target_page.h"
> @@ -23,8 +24,10 @@
> #include "qapi/qmp/qerror.h"
> #include "qapi/qobject-input-visitor.h"
> #include "qapi/qobject-output-visitor.h"
> +#include "qobject/qbool.h"
> #include "qobject/qdict.h"
> #include "qobject/qnull.h"
> +#include "qobject/qstring.h"
> #include "system/runstate.h"
> #include "migration/colo.h"
> #include "migration/cpr.h"
> @@ -1149,12 +1152,63 @@ static void
> migrate_mark_all_params_present(MigrationParameters *p)
> }
> }
>
> +static bool assert_all_params_present(MigrationParameters *params, Error
> **errp)
> +{
> + g_autoptr(QDict) d = migrate_params_to_dict(params, errp);
> + const QDictEntry *e = NULL;
> + int i = 0;
> +
> + if (!d) {
> + return false;
> + }
> +
> + for (e = qdict_first(d); e; e = qdict_next(d, e), i++) {
> + const char *key = qdict_entry_key(e);
> + const char *p;
> +
> + if (strstart(key, "tls-", &p)) {
> + QString *s = qobject_to(QString, qdict_entry_value(e));
> +
> + if (!s) {
> + break;
> + }
> + } else if (strstart(key, "has-", &p)) {
Does the qdict contain any has- field?
visit_type_MigrationParameters_members:
if (visit_optional(v, "announce-initial", &obj->has_announce_initial)) {
if (!visit_type_size(v, "announce-initial", &obj->announce_initial,
errp)) {
return false;
}
}
...
It seems the has_* fields are only used to identify existance of objects,
not converted.
> + if (qdict_haskey(d, p)) {
> + QBool *b = qobject_to(QBool, qdict_entry_value(e));
> +
> + if (!b || !qbool_get_bool(b)) {
> + break;
> + }
> + }
> + }
> + }
> +
> + if (i && !e) {
> + return true;
> + }
> +
> + /*
> + * Should never happen, but avoid asserting becase this is
> + * reachable from QMP.
IIUC as long as this fact shouldn't be changed by any possible user input,
we could still assert. But I understand you want to be careful, maybe
either (1) directly assert, or (2) change the function name,
s/assert/check/? I vote (1).
Said that, if the qdict trick didn't work it beats the whole patch.. so
IMHO we can also leave this sanity check for later too. Your call.
> + */
> + error_setg(errp, "Missing parameter. Query output will be incomplete.");
> + return false;
> +}
> +
> MigrationParameters *qmp_query_migrate_parameters(Error **errp)
> {
> MigrationState *s = migrate_get_current();
> MigrationParameters *params = QAPI_CLONE(MigrationParameters,
> &s->parameters);
>
> + /*
> + * Validate all parameters have their has_* field set to true as
> + * consequence of the initial migrate_mark_all_params_present().
> + */
> + if (!assert_all_params_present(params, errp)) {
> + return NULL;
> + }
> +
> /*
> * The block-bitmap-mapping breaks the expected API of
> * query-migrate-parameters of having all members present. To keep
> --
> 2.53.0
>
--
Peter Xu
