On Mon, Jul 28, 2025 at 12:44:53PM +0400, Marc-André Lureau wrote:
> Hi
>
> On Fri, Jul 25, 2025 at 5:46 PM Marc-André Lureau <
> marcandre.lur...@redhat.com> wrote:
>
> >
> >
> > On Fri, Jul 25, 2025 at 4:19 PM Arun Menon <arme...@redhat.com> wrote:
> >
> >> This is an incremental step in converting vmstate loading
> >> code to report error via Error objects instead of directly
> >> printing it to console/monitor.
> >> It is ensured that vmstate_subsection_load() must report an error
> >> in errp, in case of failure.
> >>
> >> Signed-off-by: Arun Menon <arme...@redhat.com>
> >> ---
> >> migration/vmstate.c | 11 ++++++++---
> >> 1 file changed, 8 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/migration/vmstate.c b/migration/vmstate.c
> >> index
> >> 5feaa3244d259874f03048326b2497e7db32e47c..aeffeafaa4fa7582076a4f2747906ddf9aca891b
> >> 100644
> >> --- a/migration/vmstate.c
> >> +++ b/migration/vmstate.c
> >> @@ -25,7 +25,7 @@ static int vmstate_subsection_save(QEMUFile *f, const
> >> VMStateDescription *vmsd,
> >> void *opaque, JSONWriter *vmdesc,
> >> Error **errp);
> >> static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription
> >> *vmsd,
> >> - void *opaque);
> >> + void *opaque, Error **errp);
> >>
> >> /* Whether this field should exist for either save or load the VM? */
> >> static bool
> >> @@ -225,7 +225,7 @@ int vmstate_load_state(QEMUFile *f, const
> >> VMStateDescription *vmsd,
> >> field++;
> >> }
> >> assert(field->flags == VMS_END);
> >> - ret = vmstate_subsection_load(f, vmsd, opaque);
> >> + ret = vmstate_subsection_load(f, vmsd, opaque, NULL);
> >> if (ret != 0) {
> >> qemu_file_set_error(f, ret);
> >> return ret;
> >> @@ -566,7 +566,7 @@ vmstate_get_subsection(const VMStateDescription *
> >> const *sub,
> >> }
> >>
> >> static int vmstate_subsection_load(QEMUFile *f, const VMStateDescription
> >> *vmsd,
> >> - void *opaque)
> >> + void *opaque, Error **errp)
> >> {
> >> trace_vmstate_subsection_load(vmsd->name);
> >>
> >> @@ -598,6 +598,8 @@ static int vmstate_subsection_load(QEMUFile *f, const
> >> VMStateDescription *vmsd,
> >> sub_vmsd = vmstate_get_subsection(vmsd->subsections, idstr);
> >> if (sub_vmsd == NULL) {
> >> trace_vmstate_subsection_load_bad(vmsd->name, idstr,
> >> "(lookup)");
> >> + error_setg(errp, "VM subsection '%s' in '%s' does not exist",
> >> + idstr, vmsd->name);
> >> return -ENOENT;
> >> }
> >> qemu_file_skip(f, 1); /* subsection */
> >> @@ -608,6 +610,9 @@ static int vmstate_subsection_load(QEMUFile *f, const
> >> VMStateDescription *vmsd,
> >> ret = vmstate_load_state(f, sub_vmsd, opaque, version_id);
> >> if (ret) {
> >> trace_vmstate_subsection_load_bad(vmsd->name, idstr,
> >> "(child)");
> >> + error_setg(errp,
> >> + "Loading VM subsection '%s' in '%s' failed : %d",
> >>
> >
> > extra space before ":"
> >
> > other than that
> > Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> >
>
> Actually, almost systematically when you introduce an extra **errp
> argument, you should ERRP_GUARD() in the function (see include/qapi/error.h
> doc). Was this discussed before? Can you update the following patches too?
ERRP_GUARD is only needed in functions which derefence errp, which should
very rarely be needed when all functions are non-void return value.
With regards,
Daniel
--
|: https://berrange.com -o- https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org -o- https://fstop138.berrange.com :|
|: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
