On Wed, Aug 20, 2025 at 12:24:49PM -0300, Fabiano Rosas wrote: > Arun Menon <arme...@redhat.com> writes: > > > Hi Fabiano, > > > > Thanks for the review. > > > > On Fri, Aug 15, 2025 at 12:41:50PM -0300, Fabiano Rosas wrote: > >> Arun Menon <arme...@redhat.com> writes: > >> > >> > 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. > >> > > >> > Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com> > >> > Signed-off-by: Arun Menon <arme...@redhat.com> > >> > --- > >> > hw/display/virtio-gpu.c | 2 +- > >> > hw/pci/pci.c | 3 ++- > >> > hw/s390x/virtio-ccw.c | 2 +- > >> > hw/scsi/spapr_vscsi.c | 2 +- > >> > hw/vfio/pci.c | 3 ++- > >> > hw/virtio/virtio-mmio.c | 3 ++- > >> > hw/virtio/virtio-pci.c | 2 +- > >> > hw/virtio/virtio.c | 4 +-- > >> > include/migration/vmstate.h | 2 +- > >> > migration/cpr.c | 5 ++-- > >> > migration/savevm.c | 6 +++-- > >> > migration/vmstate-types.c | 22 ++++++++++++---- > >> > migration/vmstate.c | 61 > >> > ++++++++++++++++++++++++++++++------------- > >> > tests/unit/test-vmstate.c | 63 > >> > ++++++++++++++++++++++++++++++++++++++------- > >> > ui/vdagent.c | 3 ++- > >> > 15 files changed, 136 insertions(+), 47 deletions(-) > >> > > >> > diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c > >> > index > >> > 0a1a625b0ea6cf26cb0d799171a57ed3d3ab2442..5dc31bc6bfb0272e29a4364ab10de2595a4bedf7 > >> > 100644 > >> > --- a/hw/display/virtio-gpu.c > >> > +++ b/hw/display/virtio-gpu.c > >> > @@ -1343,7 +1343,7 @@ static int virtio_gpu_load(QEMUFile *f, void > >> > *opaque, size_t size, > >> > } > >> > > >> > /* load & apply scanout state */ > >> > - vmstate_load_state(f, &vmstate_virtio_gpu_scanouts, g, 1); > >> > + vmstate_load_state(f, &vmstate_virtio_gpu_scanouts, g, 1, > >> > &error_fatal); > >> > > >> > return 0; > >> > } > >> > diff --git a/hw/pci/pci.c b/hw/pci/pci.c > >> > index > >> > c70b5ceebaf1f2b10768bd030526cbb518da2b8d..6be932d3bb67ff0c4808707db2a7b6378a90e82b > >> > 100644 > >> > --- a/hw/pci/pci.c > >> > +++ b/hw/pci/pci.c > >> > @@ -934,7 +934,8 @@ void pci_device_save(PCIDevice *s, QEMUFile *f) > >> > int pci_device_load(PCIDevice *s, QEMUFile *f) > >> > { > >> > int ret; > >> > - ret = vmstate_load_state(f, &vmstate_pci_device, s, s->version_id); > >> > + ret = vmstate_load_state(f, &vmstate_pci_device, s, s->version_id, > >> > + &error_fatal); > >> > /* Restore the interrupt status bit. */ > >> > pci_update_irq_status(s); > >> > return ret; > >> > diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c > >> > index > >> > d2f85b39f30f7fc82e0c600144c0a958e1269b2c..6a9641a03d5d3a38a4de7ceb9deffc0cc303bcff > >> > 100644 > >> > --- a/hw/s390x/virtio-ccw.c > >> > +++ b/hw/s390x/virtio-ccw.c > >> > @@ -1136,7 +1136,7 @@ static void virtio_ccw_save_config(DeviceState *d, > >> > QEMUFile *f) > >> > static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f) > >> > { > >> > VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d); > >> > - return vmstate_load_state(f, &vmstate_virtio_ccw_dev, dev, 1); > >> > + return vmstate_load_state(f, &vmstate_virtio_ccw_dev, dev, 1, > >> > &error_fatal); > >> > } > >> > > >> > static void virtio_ccw_pre_plugged(DeviceState *d, Error **errp) > >> > diff --git a/hw/scsi/spapr_vscsi.c b/hw/scsi/spapr_vscsi.c > >> > index > >> > 20f70fb2729de78b9636a6b8c869695dab4f8902..8c896022d324f51962605288d6d6df1648c83cde > >> > 100644 > >> > --- a/hw/scsi/spapr_vscsi.c > >> > +++ b/hw/scsi/spapr_vscsi.c > >> > @@ -648,7 +648,7 @@ static void *vscsi_load_request(QEMUFile *f, > >> > SCSIRequest *sreq) > >> > assert(!req->active); > >> > > >> > memset(req, 0, sizeof(*req)); > >> > - rc = vmstate_load_state(f, &vmstate_spapr_vscsi_req, req, 1); > >> > + rc = vmstate_load_state(f, &vmstate_spapr_vscsi_req, req, 1, > >> > &error_fatal); > >> > if (rc) { > >> > fprintf(stderr, "VSCSI: failed loading request tag#%u\n", > >> > sreq->tag); > >> > return NULL; > >> > diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c > >> > index > >> > 4fa692c1a32bcfa4e4939e5fcb64f2bf19905b3b..0be54762cdcbdb4780b8228b0bdf7fc6bd74dd57 > >> > 100644 > >> > --- a/hw/vfio/pci.c > >> > +++ b/hw/vfio/pci.c > >> > @@ -2795,7 +2795,8 @@ static int vfio_pci_load_config(VFIODevice > >> > *vbasedev, QEMUFile *f) > >> > old_addr[bar] = pdev->io_regions[bar].addr; > >> > } > >> > > >> > - ret = vmstate_load_state(f, &vmstate_vfio_pci_config, vdev, 1); > >> > + ret = vmstate_load_state(f, &vmstate_vfio_pci_config, vdev, 1, > >> > + &error_fatal); > >> > if (ret) { > >> > return ret; > >> > } > >> > diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c > >> > index > >> > 532c67107ba1d2978a76cf49f9cdc1de1dea3e11..0a688909fc606a3c9fde933667ae8c309ab527d0 > >> > 100644 > >> > --- a/hw/virtio/virtio-mmio.c > >> > +++ b/hw/virtio/virtio-mmio.c > >> > @@ -34,6 +34,7 @@ > >> > #include "qemu/error-report.h" > >> > #include "qemu/log.h" > >> > #include "trace.h" > >> > +#include "qapi/error.h" > >> > > >> > static bool virtio_mmio_ioeventfd_enabled(DeviceState *d) > >> > { > >> > @@ -619,7 +620,7 @@ static int virtio_mmio_load_extra_state(DeviceState > >> > *opaque, QEMUFile *f) > >> > { > >> > VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque); > >> > > >> > - return vmstate_load_state(f, &vmstate_virtio_mmio, proxy, 1); > >> > + return vmstate_load_state(f, &vmstate_virtio_mmio, proxy, 1, > >> > &error_fatal); > >> > } > >> > > >> > static bool virtio_mmio_has_extra_state(DeviceState *opaque) > >> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > >> > index > >> > 767216d795998708f5716a23ae16c79cd90ff489..b04faa1e5c91b5cef40e54ec41d92422d16bfc13 > >> > 100644 > >> > --- a/hw/virtio/virtio-pci.c > >> > +++ b/hw/virtio/virtio-pci.c > >> > @@ -161,7 +161,7 @@ static int virtio_pci_load_extra_state(DeviceState > >> > *d, QEMUFile *f) > >> > { > >> > VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d); > >> > > >> > - return vmstate_load_state(f, &vmstate_virtio_pci, proxy, 1); > >> > + return vmstate_load_state(f, &vmstate_virtio_pci, proxy, 1, > >> > &error_fatal); > >> > } > >> > > >> > static void virtio_pci_save_queue(DeviceState *d, int n, QEMUFile *f) > >> > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > >> > index > >> > 9a81ad912e013fc254899c4e55cff1f76a6112a4..6bcafb338d1b5becadcacf092ba33a6ae4c3d194 > >> > 100644 > >> > --- a/hw/virtio/virtio.c > >> > +++ b/hw/virtio/virtio.c > >> > @@ -3327,14 +3327,14 @@ virtio_load(VirtIODevice *vdev, QEMUFile *f, int > >> > version_id) > >> > } > >> > > >> > if (vdc->vmsd) { > >> > - ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id); > >> > + ret = vmstate_load_state(f, vdc->vmsd, vdev, version_id, > >> > &error_fatal); > >> > if (ret) { > >> > return ret; > >> > } > >> > } > >> > > >> > /* Subsections */ > >> > - ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1); > >> > + ret = vmstate_load_state(f, &vmstate_virtio, vdev, 1, &error_fatal); > >> > if (ret) { > >> > return ret; > >> > } > >> > diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h > >> > index > >> > 1ff7bd9ac425ba67cd5ca7ad97bcf570f9e19abe..056781b1c21e737583f081594d9f88b32adfd674 > >> > 100644 > >> > --- a/include/migration/vmstate.h > >> > +++ b/include/migration/vmstate.h > >> > @@ -1196,7 +1196,7 @@ extern const VMStateInfo vmstate_info_qlist; > >> > } > >> > > >> > int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd, > >> > - void *opaque, int version_id); > >> > + void *opaque, int version_id, Error **errp); > >> > int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, > >> > void *opaque, JSONWriter *vmdesc); > >> > int vmstate_save_state_with_err(QEMUFile *f, const VMStateDescription > >> > *vmsd, > >> > diff --git a/migration/cpr.c b/migration/cpr.c > >> > index > >> > 42ad0b0d500e5de57faf0c6517e216b2d1c0cacf..bdb24736f44e91ba59b6e622a315597c97e7f64d > >> > 100644 > >> > --- a/migration/cpr.c > >> > +++ b/migration/cpr.c > >> > @@ -202,6 +202,7 @@ int cpr_state_save(MigrationChannel *channel, Error > >> > **errp) > >> > > >> > int cpr_state_load(MigrationChannel *channel, Error **errp) > >> > { > >> > + ERRP_GUARD(); > >> > int ret; > >> > uint32_t v; > >> > QEMUFile *f; > >> > @@ -233,9 +234,9 @@ int cpr_state_load(MigrationChannel *channel, Error > >> > **errp) > >> > return -ENOTSUP; > >> > } > >> > > >> > - ret = vmstate_load_state(f, &vmstate_cpr_state, &cpr_state, 1); > >> > + ret = vmstate_load_state(f, &vmstate_cpr_state, &cpr_state, 1, > >> > errp); > >> > if (ret) { > >> > - error_setg(errp, "vmstate_load_state error %d", ret); > >> > + error_prepend(errp, "vmstate_load_state error %d: ", ret); > >> > qemu_fclose(f); > >> > return ret; > >> > } > >> > diff --git a/migration/savevm.c b/migration/savevm.c > >> > index > >> > fabbeb296ae987d0c06ba6dafda63720205fecfd..cb64f2855d46aaa7c617b3e4079a2c9e566079b2 > >> > 100644 > >> > --- a/migration/savevm.c > >> > +++ b/migration/savevm.c > >> > @@ -969,7 +969,8 @@ static int vmstate_load(QEMUFile *f, SaveStateEntry > >> > *se) > >> > if (!se->vmsd) { /* Old style */ > >> > return se->ops->load_state(f, se->opaque, se->load_version_id); > >> > } > >> > - return vmstate_load_state(f, se->vmsd, se->opaque, > >> > se->load_version_id); > >> > + return vmstate_load_state(f, se->vmsd, se->opaque, > >> > se->load_version_id, > >> > + &error_fatal); > >> > } > >> > > >> > static void vmstate_save_old_style(QEMUFile *f, SaveStateEntry *se, > >> > @@ -2839,7 +2840,8 @@ static int qemu_loadvm_state_header(QEMUFile *f) > >> > error_report("Configuration section missing"); > >> > return -EINVAL; > >> > } > >> > - ret = vmstate_load_state(f, &vmstate_configuration, > >> > &savevm_state, 0); > >> > + ret = vmstate_load_state(f, &vmstate_configuration, > >> > &savevm_state, 0, > >> > + &error_fatal); > >> > > >> > if (ret) { > >> > return ret; > >> > diff --git a/migration/vmstate-types.c b/migration/vmstate-types.c > >> > index > >> > 741a588b7e18c6d37724b08a0101edc8bc74a0a5..f41670cc853c5b41ccc8def354886a8e5c1451fd > >> > 100644 > >> > --- a/migration/vmstate-types.c > >> > +++ b/migration/vmstate-types.c > >> > @@ -19,6 +19,7 @@ > >> > #include "qemu/error-report.h" > >> > #include "qemu/queue.h" > >> > #include "trace.h" > >> > +#include "qapi/error.h" > >> > > >> > /* bool */ > >> > > >> > @@ -543,13 +544,17 @@ static int get_tmp(QEMUFile *f, void *pv, size_t > >> > size, > >> > const VMStateField *field) > >> > { > >> > int ret; > >> > + Error *local_err = NULL; > >> > const VMStateDescription *vmsd = field->vmsd; > >> > int version_id = field->version_id; > >> > void *tmp = g_malloc(size); > >> > > >> > /* Writes the parent field which is at the start of the tmp */ > >> > *(void **)tmp = pv; > >> > - ret = vmstate_load_state(f, vmsd, tmp, version_id); > >> > + ret = vmstate_load_state(f, vmsd, tmp, version_id, &local_err); > >> > + if (ret < 0) { > >> > + warn_report_err(local_err); > >> > + } > >> > g_free(tmp); > >> > return ret; > >> > } > >> > @@ -626,6 +631,7 @@ static int get_qtailq(QEMUFile *f, void *pv, size_t > >> > unused_size, > >> > const VMStateField *field) > >> > { > >> > int ret = 0; > >> > + Error *local_err = NULL; > >> > const VMStateDescription *vmsd = field->vmsd; > >> > /* size of a QTAILQ element */ > >> > size_t size = field->size; > >> > @@ -649,8 +655,9 @@ static int get_qtailq(QEMUFile *f, void *pv, size_t > >> > unused_size, > >> > > >> > while (qemu_get_byte(f)) { > >> > elm = g_malloc(size); > >> > - ret = vmstate_load_state(f, vmsd, elm, version_id); > >> > + ret = vmstate_load_state(f, vmsd, elm, version_id, &local_err); > >> > if (ret) { > >> > + warn_report_err(local_err); > >> > return ret; > >> > } > >> > QTAILQ_RAW_INSERT_TAIL(pv, elm, entry_offset); > >> > @@ -772,6 +779,7 @@ static int get_gtree(QEMUFile *f, void *pv, size_t > >> > unused_size, > >> > GTree *tree = *pval; > >> > void *key, *val; > >> > int ret = 0; > >> > + Error *local_err = NULL; > >> > > >> > /* in case of direct key, the key vmsd can be {}, ie. check fields > >> > */ > >> > if (!direct_key && version_id > key_vmsd->version_id) { > >> > @@ -803,18 +811,20 @@ static int get_gtree(QEMUFile *f, void *pv, size_t > >> > unused_size, > >> > key = (void *)(uintptr_t)qemu_get_be64(f); > >> > } else { > >> > key = g_malloc0(key_size); > >> > - ret = vmstate_load_state(f, key_vmsd, key, version_id); > >> > + ret = vmstate_load_state(f, key_vmsd, key, version_id, > >> > &local_err); > >> > if (ret) { > >> > error_report("%s : failed to load %s (%d)", > >> > field->name, key_vmsd->name, ret); > >> > + warn_report_err(local_err); > >> > goto key_error; > >> > } > >> > } > >> > val = g_malloc0(val_size); > >> > - ret = vmstate_load_state(f, val_vmsd, val, version_id); > >> > + ret = vmstate_load_state(f, val_vmsd, val, version_id, > >> > &local_err); > >> > if (ret) { > >> > error_report("%s : failed to load %s (%d)", > >> > field->name, val_vmsd->name, ret); > >> > + warn_report_err(local_err); > >> > goto val_error; > >> > } > >> > g_tree_insert(tree, key, val); > >> > @@ -872,6 +882,7 @@ static int get_qlist(QEMUFile *f, void *pv, size_t > >> > unused_size, > >> > const VMStateField *field) > >> > { > >> > int ret = 0; > >> > + Error *local_err = NULL; > >> > const VMStateDescription *vmsd = field->vmsd; > >> > /* size of a QLIST element */ > >> > size_t size = field->size; > >> > @@ -892,10 +903,11 @@ static int get_qlist(QEMUFile *f, void *pv, size_t > >> > unused_size, > >> > > >> > while (qemu_get_byte(f)) { > >> > elm = g_malloc(size); > >> > - ret = vmstate_load_state(f, vmsd, elm, version_id); > >> > + ret = vmstate_load_state(f, vmsd, elm, version_id, &local_err); > >> > if (ret) { > >> > error_report("%s: failed to load %s (%d)", field->name, > >> > vmsd->name, ret); > >> > + warn_report_err(local_err); > >> > g_free(elm); > >> > return ret; > >> > } > >> > diff --git a/migration/vmstate.c b/migration/vmstate.c > >> > index > >> > 6108c7fe283a5013ce42ea9987723c489aef26a2..1cd609a1d598995af1e51d1f4d58d68133f1426d > >> > 100644 > >> > --- a/migration/vmstate.c > >> > +++ b/migration/vmstate.c > >> > @@ -132,29 +132,34 @@ 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) > >> > { > >> > + ERRP_GUARD(); > >> > 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 for: '%s', " > >> > >> "VM" pre load is a little ambiguous. Simply "pre load" or "pre load > >> hook" is better. > > Sure, will do this. > >> > >> > + "version_id: %d, minimum version_id: %d, ret: > >> > %d", > >> > + vmsd->name, vmsd->version_id, > >> > vmsd->minimum_version_id, > >> > + ret); > >> > return ret; > >> > } > >> > } > >> > @@ -192,13 +197,20 @@ 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); > >> > + if (ret < 0) { > >> > + error_setg(errp, > >> > + "Failed to get info for %s: %d", > >> > + inner_field->name, ret); > >> > >> "get info" is not correct. This is the type-specific getter > >> invocation. Because the migration (for the most part) is a stream, each > >> type provides it's own getter which knows about the size of the field > >> and any particularities such as magic values. So: > >> > >> error_setg(errp, "Failed to load element of type %s for %s: %d", > >> info->name, inner_field->name, ret); > > yes, will change the message. Thanks. > >> > >> > + } > >> > } > >> > > >> > /* If we used a fake temp field.. free it now */ > >> > @@ -208,30 +220,42 @@ int vmstate_load_state(QEMUFile *f, const > >> > VMStateDescription *vmsd, > >> > > >> > if (ret >= 0) { > >> > ret = qemu_file_get_error(f); > >> > + if (ret < 0) { > >> > + error_setg(errp, "Failed to load %s state: %d", > >> > + vmsd->name, ret); > >> > >> We could go a little more specific here, it's useful to know whether the > >> error was on the transport side, rather than something logical with the > >> migrated data. I don't really care about the actual string, but one > >> suggestion is "stream error": > >> > >> error_setg(errp, "Failed to load %s state: stream error: %d", > >> vmsd->name, ret); > > yes, will add stream error. Thanks. > >> > >> > + } > >> > } > >> > if (ret < 0) { > >> > qemu_file_set_error(f, ret); > >> > - error_report("Failed to load %s:%s", vmsd->name, > >> > - field->name); > >> > + error_prepend(errp, > >> > + "Failed to load %s:%s version_id: %d: > >> > ", > >> > >> Usage of : is inconsistent with below / > > Since we used error_prepend here, we need an extra space after the colon ':' > > That way the next error string looks readable. > > Right, that's not what I'm talking about. What's inconsistent is: %s:%s > vs. %s/%s > > >> > >> > + vmsd->name, field->name, > >> > vmsd->version_id); > >> > 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 > >> > version_id: %d", > > here^ I see, I shall amend. It was copied as is from error_report(). Thanks. >
Regards, Arun