On Sat, Feb 21, 2026 at 12:02:05AM +0300, Vladimir Sementsov-Ogievskiy wrote:
> Simplify vmstate_save_state() which is rather big, and simplify further
> refactoring.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy
I wonder how hard it is to have this helper also cover the rest in the loop
over elements, on e.g. VMS_ARRAY_OF_POINTER, vmdesc_loop being able to
change, and all the nullptr handling.
I had a feeling that you intentionally skipped those because it'll not be
as trivial - I think it's fine, but IIUC we can always figure a way out.
Can be done later. Agree this is an improvement already,
Reviewed-by: Peter Xu
> ---
> migration/vmstate.c | 40 +---
> 1 file changed, 25 insertions(+), 15 deletions(-)
>
> diff --git a/migration/vmstate.c b/migration/vmstate.c
> index 810b131f18..d8c30830d6 100644
> --- a/migration/vmstate.c
> +++ b/migration/vmstate.c
> @@ -26,6 +26,9 @@ static int vmstate_subsection_save(QEMUFile *f, const
> VMStateDescription *vmsd,
> Error **errp);
> static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription
> *vmsd,
> void *opaque, Error **errp);
> +static int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
> +void *opaque, JSONWriter *vmdesc,
> +int version_id, Error **errp);
>
> /* Whether this field should exist for either save or load the VM? */
> static bool
> @@ -450,6 +453,26 @@ static bool vmstate_pre_save(const VMStateDescription
> *vmsd, void *opaque,
> return true;
> }
>
> +static bool vmstate_save_field(QEMUFile *f, void *pv, size_t size,
> + const VMStateField *field,
> + JSONWriter *vmdesc, Error **errp)
> +{
> +if (field->flags & VMS_STRUCT) {
> +return vmstate_save_state(f, field->vmsd, pv, vmdesc, errp) >= 0;
> +} else if (field->flags & VMS_VSTRUCT) {
> +return vmstate_save_state_v(f, field->vmsd, pv, vmdesc,
> +field->struct_version_id,
> +errp) >= 0;
> +}
> +
> +if (field->info->put(f, pv, size, field, vmdesc) < 0) {
> +error_setg(errp, "put failed");
> +return false;
> +}
> +
> +return true;
> +}
> +
> static int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
> void *opaque, JSONWriter *vmdesc,
> int version_id, Error **errp)
> @@ -542,21 +565,8 @@ static int vmstate_save_state_v(QEMUFile *f, const
> VMStateDescription *vmsd,
> vmsd_desc_field_start(vmsd, vmdesc_loop, inner_field,
>i, max_elems);
>
> -if (inner_field->flags & VMS_STRUCT) {
> -ret = vmstate_save_state(f, inner_field->vmsd,
> - curr_elem, vmdesc_loop, errp);
> -} else if (inner_field->flags & VMS_VSTRUCT) {
> -ret = vmstate_save_state_v(f, inner_field->vmsd,
> - curr_elem, vmdesc_loop,
> -
> inner_field->struct_version_id,
> - errp);
> -} else {
> -ret = inner_field->info->put(f, curr_elem, size,
> - inner_field, vmdesc_loop);
> -if (ret < 0) {
> -error_setg(errp, "put failed");
> -}
> -}
> +ret = vmstate_save_field(f, curr_elem, size, inner_field,
> + vmdesc_loop, errp) ? 0 : -EINVAL;
>
> written_bytes = qemu_file_transferred(f) - old_offset;
> vmsd_desc_field_end(vmsd, vmdesc_loop, inner_field,
> --
> 2.52.0
>
--
Peter Xu
