On Thu, Jul 17, 2025 at 06:07:25AM +0530, Arun Menon 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_load_state() must report an error
> in errp, in case of failure.
>
> Signed-off-by: Arun Menon <arme...@redhat.com>
> ---
> hw/display/virtio-gpu.c | 2 +-
> hw/pci/pci.c | 2 +-
> hw/s390x/virtio-ccw.c | 2 +-
> hw/scsi/spapr_vscsi.c | 2 +-
> hw/vfio/pci.c | 2 +-
> hw/virtio/virtio-mmio.c | 2 +-
> hw/virtio/virtio-pci.c | 2 +-
> hw/virtio/virtio.c | 4 ++--
> include/migration/vmstate.h | 2 +-
> migration/cpr.c | 4 ++--
> migration/savevm.c | 6 ++++--
> migration/vmstate-types.c | 10 +++++-----
> migration/vmstate.c | 43 +++++++++++++++++++++++++++----------------
> tests/unit/test-vmstate.c | 18 +++++++++---------
> ui/vdagent.c | 2 +-
> 15 files changed, 58 insertions(+), 45 deletions(-)
>
> diff --git a/migration/vmstate.c b/migration/vmstate.c
> index
> 526668a020562f303d2ddf030b1c8466659b67be..078a00003023cc248fb16f05017d4c4251fd86df
> 100644
> --- a/migration/vmstate.c
> +++ b/migration/vmstate.c
> @@ -132,29 +132,30 @@ static void vmstate_handle_alloc(void *ptr, const
> VMStateField *field,
> }
>
> int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
> - void *opaque, int version_id)
> + void *opaque, int version_id, Error **errp)
> {
> const VMStateField *field = vmsd->fields;
> int ret = 0;
>
> trace_vmstate_load_state(vmsd->name, version_id);
> if (version_id > vmsd->version_id) {
> - error_report("%s: incoming version_id %d is too new "
> - "for local version_id %d",
> - vmsd->name, version_id, vmsd->version_id);
> + error_setg(errp, "%s: incoming version_id %d is too new "
> + "for local version_id %d",
> + vmsd->name, version_id, vmsd->version_id);
> trace_vmstate_load_state_end(vmsd->name, "too new", -EINVAL);
> return -EINVAL;
> }
> if (version_id < vmsd->minimum_version_id) {
> - error_report("%s: incoming version_id %d is too old "
> - "for local minimum version_id %d",
> - vmsd->name, version_id, vmsd->minimum_version_id);
> + error_setg(errp, "%s: incoming version_id %d is too old "
> + "for local minimum version_id %d",
> + vmsd->name, version_id, vmsd->minimum_version_id);
> trace_vmstate_load_state_end(vmsd->name, "too old", -EINVAL);
> return -EINVAL;
> }
> if (vmsd->pre_load) {
> ret = vmsd->pre_load(opaque);
> if (ret) {
> + error_setg(errp, "VM pre load failed : %d", ret);
Suggest including
vmsd->name, version_id, vmsd->minimum_version_id
as those are all relevant context which may aid in diagnosing
this error.
> return ret;
> }
> }
> @@ -192,10 +193,12 @@ int vmstate_load_state(QEMUFile *f, const
> VMStateDescription *vmsd,
>
> if (inner_field->flags & VMS_STRUCT) {
> ret = vmstate_load_state(f, inner_field->vmsd, curr_elem,
> - inner_field->vmsd->version_id);
> + inner_field->vmsd->version_id,
> + errp);
> } else if (inner_field->flags & VMS_VSTRUCT) {
> ret = vmstate_load_state(f, inner_field->vmsd, curr_elem,
> - inner_field->struct_version_id);
> + inner_field->struct_version_id,
> + errp);
> } else {
> ret = inner_field->info->get(f, curr_elem, size,
> inner_field);
This should have the "error_setg" call, so...
> @@ -211,27 +214,35 @@ int vmstate_load_state(QEMUFile *f, const
> VMStateDescription *vmsd,
> }
> if (ret < 0) {
> qemu_file_set_error(f, ret);
> - error_report("Failed to load %s:%s", vmsd->name,
> - field->name);
> + if (errp != NULL) {
> + error_prepend(errp, "Failed to load %s:%s ",
> vmsd->name,
> + field->name);
> + } else {
> + error_setg(errp, "Failed to load %s:%s", vmsd->name,
> + field->name);
> + }
...this should exclusively do error_prepend.
Also include the 'version_id' here as an bit of extra context.
> trace_vmstate_load_field_error(field->name, ret);
> return ret;
> }
> }
> } else if (field->flags & VMS_MUST_EXIST) {
> - error_report("Input validation failed: %s/%s",
> - vmsd->name, field->name);
> + error_setg(errp, "Input validation failed: %s/%s",
> + vmsd->name, field->name);
Inlucde the version_id too
> return -1;
> }
> field++;
> }
> assert(field->flags == VMS_END);
> - ret = vmstate_subsection_load(f, vmsd, opaque, NULL);
> + ret = vmstate_subsection_load(f, vmsd, opaque, errp);
> if (ret != 0) {
> qemu_file_set_error(f, ret);
> return ret;
> }
> if (vmsd->post_load) {
> ret = vmsd->post_load(opaque, version_id);
> + if (ret < 0) {
> + error_setg(errp, "VM Post load failed : %d", ret);
> + }
Suggest including
vmsd->name, version_id, vmsd->minimum_version_id
> }
> trace_vmstate_load_state_end(vmsd->name, "end", ret);
> return ret;
With regards,
Daniel
--
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