Hi
On Tue, Aug 5, 2025 at 10:31 PM Arun Menon <arme...@redhat.com> wrote:
> This commit removes the redundant vmstate_save_state_with_err()
> function.
>
> Previously, commit 969298f9d7 introduced vmstate_save_state_with_err()
> to handle error propagation, while vmstate_save_state() existed for
> non-error scenarios.
> This is because there were code paths where vmstate_save_state_v()
> (called internally by vmstate_save_state) did not explicitly set
> errors on failure.
>
> This change unifies error handling by
> - updating vmstate_save_state() to accept an Error **errp argument.
> - vmstate_save_state_v() ensures errors are set directly within the errp
> object, eliminating the need for two separate functions. Specifically
> errors are handled by storing them in errp in vmstate_save_dispatch()
>
> All calls to vmstate_save_state_with_err() are replaced with
> vmstate_save_state(). This simplifies the API and improves code
> maintainability.
>
> Signed-off-by: Arun Menon <arme...@redhat.com>
>
I realize that vmstate_save_state() callers progressively became silent on
error with this series (switching to error_report to error_set). I suggest
you make a preliminary patch to make vmstate_save_state() verbose by
passing &error_warn to vmstate_save_state_v. wdyt?
patch lgtm otherwise
> ---
> hw/display/virtio-gpu.c | 3 ++-
> hw/pci/pci.c | 2 +-
> hw/s390x/virtio-ccw.c | 2 +-
> hw/scsi/spapr_vscsi.c | 2 +-
> hw/vfio/pci.c | 4 ++--
> 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 | 5 +++--
> migration/savevm.c | 7 ++++---
> migration/vmstate-types.c | 12 +++++++-----
> migration/vmstate.c | 18 ++++++++----------
> tests/unit/test-vmstate.c | 8 +++++---
> ui/vdagent.c | 3 ++-
> 15 files changed, 40 insertions(+), 36 deletions(-)
>
> diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
> index
> 5ff9f5e6dc0b6b112e36170318c900f893a73c5e..bddb26fa21312e5d0b2b6412cdf2a6c28dd06eb3
> 100644
> --- a/hw/display/virtio-gpu.c
> +++ b/hw/display/virtio-gpu.c
> @@ -1246,7 +1246,8 @@ static int virtio_gpu_save(QEMUFile *f, void
> *opaque, size_t size,
> }
> qemu_put_be32(f, 0); /* end of list */
>
> - return vmstate_save_state(f, &vmstate_virtio_gpu_scanouts, g, NULL);
> + return vmstate_save_state(f, &vmstate_virtio_gpu_scanouts, g, NULL,
> + &error_warn);
> }
>
> static bool virtio_gpu_load_restore_mapping(VirtIOGPU *g,
> diff --git a/hw/pci/pci.c b/hw/pci/pci.c
> index
> 80545189980f176ca6a3dc9abce7043c8bc2708c..f7fb3931ff190c25ffa665ba80abe7737dbefdb6
> 100644
> --- a/hw/pci/pci.c
> +++ b/hw/pci/pci.c
> @@ -926,7 +926,7 @@ void pci_device_save(PCIDevice *s, QEMUFile *f)
> * This makes us compatible with old devices
> * which never set or clear this bit. */
> s->config[PCI_STATUS] &= ~PCI_STATUS_INTERRUPT;
> - vmstate_save_state(f, &vmstate_pci_device, s, NULL);
> + vmstate_save_state(f, &vmstate_pci_device, s, NULL, &error_warn);
> /* Restore the interrupt status bit. */
> pci_update_irq_status(s);
> }
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index
> bafcb9b76d81749925e31b5a0a1320b3332ad2cf..14304fd3e8901d28a7788266df2c7ef7334b691c
> 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -1130,7 +1130,7 @@ static int virtio_ccw_load_queue(DeviceState *d, int
> n, QEMUFile *f)
> static void virtio_ccw_save_config(DeviceState *d, QEMUFile *f)
> {
> VirtioCcwDevice *dev = VIRTIO_CCW_DEVICE(d);
> - vmstate_save_state(f, &vmstate_virtio_ccw_dev, dev, NULL);
> + vmstate_save_state(f, &vmstate_virtio_ccw_dev, dev, NULL,
> &error_warn);
> }
>
> static int virtio_ccw_load_config(DeviceState *d, QEMUFile *f)
> diff --git a/hw/scsi/spapr_vscsi.c b/hw/scsi/spapr_vscsi.c
> index
> a4812afd0cc7c495080ef03a531c7d279af29b33..2204beb40c7cdc827db2bf86fb8612d8c09999ed
> 100644
> --- a/hw/scsi/spapr_vscsi.c
> +++ b/hw/scsi/spapr_vscsi.c
> @@ -630,7 +630,7 @@ static void vscsi_save_request(QEMUFile *f,
> SCSIRequest *sreq)
> vscsi_req *req = sreq->hba_private;
> assert(req->active);
>
> - vmstate_save_state(f, &vmstate_spapr_vscsi_req, req, NULL);
> + vmstate_save_state(f, &vmstate_spapr_vscsi_req, req, NULL,
> &error_warn);
>
> trace_spapr_vscsi_save_request(req->qtag, req->cur_desc_num,
> req->cur_desc_offset);
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index
> 04d385d7674f444844beeee7364ee0424f762758..8e2b6d611de8efdf98235355226f5e5a6fd87b19
> 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -2780,8 +2780,8 @@ static int vfio_pci_save_config(VFIODevice
> *vbasedev, QEMUFile *f, Error **errp)
> {
> VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
>
> - return vmstate_save_state_with_err(f, &vmstate_vfio_pci_config, vdev,
> NULL,
> - errp);
> + return vmstate_save_state(f, &vmstate_vfio_pci_config, vdev, NULL,
> + errp);
> }
>
> static int vfio_pci_load_config(VFIODevice *vbasedev, QEMUFile *f)
> diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
> index
> f14f0487fec3ed30d2cc3aec96950c2121265716..58957990743f061e78d0eafcfcb6cc5989252edc
> 100644
> --- a/hw/virtio/virtio-mmio.c
> +++ b/hw/virtio/virtio-mmio.c
> @@ -613,7 +613,7 @@ static void virtio_mmio_save_extra_state(DeviceState
> *opaque, QEMUFile *f)
> {
> VirtIOMMIOProxy *proxy = VIRTIO_MMIO(opaque);
>
> - vmstate_save_state(f, &vmstate_virtio_mmio, proxy, NULL);
> + vmstate_save_state(f, &vmstate_virtio_mmio, proxy, NULL, &error_warn);
> }
>
> static int virtio_mmio_load_extra_state(DeviceState *opaque, QEMUFile *f)
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index
> 07f144d6d1bfbb561b28015de71762601080dc23..0826399cdfbf09b5b3f9acd9967de3417858c9d2
> 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -154,7 +154,7 @@ static void virtio_pci_save_extra_state(DeviceState
> *d, QEMUFile *f)
> {
> VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
>
> - vmstate_save_state(f, &vmstate_virtio_pci, proxy, NULL);
> + vmstate_save_state(f, &vmstate_virtio_pci, proxy, NULL, &error_warn);
> }
>
> static int virtio_pci_load_extra_state(DeviceState *d, QEMUFile *f)
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index
> aac317a93c3cd55ece9b0fd858c7b2459f8242f9..552e167529e9c22fb4cba2b445ffad85fef619f3
> 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -3025,14 +3025,14 @@ int virtio_save(VirtIODevice *vdev, QEMUFile *f)
> }
>
> if (vdc->vmsd) {
> - int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL);
> + int ret = vmstate_save_state(f, vdc->vmsd, vdev, NULL,
> &error_warn);
> if (ret) {
> return ret;
> }
> }
>
> /* Subsections */
> - return vmstate_save_state(f, &vmstate_virtio, vdev, NULL);
> + return vmstate_save_state(f, &vmstate_virtio, vdev, NULL,
> &error_warn);
> }
>
> /* A wrapper for use as a VMState .put function */
> diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
> index
> 056781b1c21e737583f081594d9f88b32adfd674..5fe9bbf39058d0cf97c1adab54cc516dbe8dc32a
> 100644
> --- a/include/migration/vmstate.h
> +++ b/include/migration/vmstate.h
> @@ -1198,8 +1198,6 @@ extern const VMStateInfo vmstate_info_qlist;
> int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
> 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,
> void *opaque, JSONWriter *vmdesc, Error **errp);
> int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
> void *opaque, JSONWriter *vmdesc,
> diff --git a/migration/cpr.c b/migration/cpr.c
> index
> bdb24736f44e91ba59b6e622a315597c97e7f64d..d48f013dac21b531e41a26f4bb33eefe32097757
> 100644
> --- a/migration/cpr.c
> +++ b/migration/cpr.c
> @@ -163,6 +163,7 @@ bool cpr_is_incoming(void)
>
> int cpr_state_save(MigrationChannel *channel, Error **errp)
> {
> + ERRP_GUARD();
> int ret;
> QEMUFile *f;
> MigMode mode = migrate_mode();
> @@ -182,9 +183,9 @@ int cpr_state_save(MigrationChannel *channel, Error
> **errp)
> qemu_put_be32(f, QEMU_CPR_FILE_MAGIC);
> qemu_put_be32(f, QEMU_CPR_FILE_VERSION);
>
> - ret = vmstate_save_state(f, &vmstate_cpr_state, &cpr_state, 0);
> + ret = vmstate_save_state(f, &vmstate_cpr_state, &cpr_state, 0, errp);
> if (ret) {
> - error_setg(errp, "vmstate_save_state error %d", ret);
> + error_prepend(errp, "vmstate_save_state error %d: ", ret);
> qemu_fclose(f);
> return ret;
> }
> diff --git a/migration/savevm.c b/migration/savevm.c
> index
> 4df50fb5c674e56c0173c357c1e23367373e2114..3cb9c34efb22fdcb2b05cf1fefcb6fbd80cadca5
> 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1056,8 +1056,8 @@ static int vmstate_save(QEMUFile *f, SaveStateEntry
> *se, JSONWriter *vmdesc,
> if (!se->vmsd) {
> vmstate_save_old_style(f, se, vmdesc);
> } else {
> - ret = vmstate_save_state_with_err(f, se->vmsd, se->opaque, vmdesc,
> - errp);
> + ret = vmstate_save_state(f, se->vmsd, se->opaque, vmdesc,
> + errp);
> if (ret) {
> return ret;
> }
> @@ -1303,7 +1303,8 @@ void qemu_savevm_state_header(QEMUFile *f)
> json_writer_start_object(vmdesc, "configuration");
> }
>
> - vmstate_save_state(f, &vmstate_configuration, &savevm_state,
> vmdesc);
> + vmstate_save_state(f, &vmstate_configuration, &savevm_state,
> vmdesc,
> + &error_warn);
>
> if (vmdesc) {
> json_writer_end_object(vmdesc);
> diff --git a/migration/vmstate-types.c b/migration/vmstate-types.c
> index
> e2020a733d0921d748b6f832a193e5de8d302d5f..2b88dc145ab32072f09845cee95b79aad7ac3cb2
> 100644
> --- a/migration/vmstate-types.c
> +++ b/migration/vmstate-types.c
> @@ -564,7 +564,7 @@ static int put_tmp(QEMUFile *f, void *pv, size_t size,
>
> /* Writes the parent field which is at the start of the tmp */
> *(void **)tmp = pv;
> - ret = vmstate_save_state(f, vmsd, tmp, vmdesc);
> + ret = vmstate_save_state(f, vmsd, tmp, vmdesc, &error_warn);
> g_free(tmp);
>
> return ret;
> @@ -675,7 +675,7 @@ static int put_qtailq(QEMUFile *f, void *pv, size_t
> unused_size,
>
> QTAILQ_RAW_FOREACH(elm, pv, entry_offset) {
> qemu_put_byte(f, true);
> - ret = vmstate_save_state(f, vmsd, elm, vmdesc);
> + ret = vmstate_save_state(f, vmsd, elm, vmdesc, &error_warn);
> if (ret) {
> return ret;
> }
> @@ -712,7 +712,8 @@ static gboolean put_gtree_elem(gpointer key, gpointer
> value, gpointer data)
> if (!capsule->key_vmsd) {
> qemu_put_be64(f, (uint64_t)(uintptr_t)(key)); /* direct key */
> } else {
> - ret = vmstate_save_state(f, capsule->key_vmsd, key,
> capsule->vmdesc);
> + ret = vmstate_save_state(f, capsule->key_vmsd, key,
> capsule->vmdesc,
> + &error_warn);
> if (ret) {
> capsule->ret = ret;
> return true;
> @@ -720,7 +721,8 @@ static gboolean put_gtree_elem(gpointer key, gpointer
> value, gpointer data)
> }
>
> /* put the data */
> - ret = vmstate_save_state(f, capsule->val_vmsd, value,
> capsule->vmdesc);
> + ret = vmstate_save_state(f, capsule->val_vmsd, value, capsule->vmdesc,
> + &error_warn);
> if (ret) {
> capsule->ret = ret;
> return true;
> @@ -856,7 +858,7 @@ static int put_qlist(QEMUFile *f, void *pv, size_t
> unused_size,
> trace_put_qlist(field->name, vmsd->name, vmsd->version_id);
> QLIST_RAW_FOREACH(elm, pv, entry_offset) {
> qemu_put_byte(f, true);
> - ret = vmstate_save_state(f, vmsd, elm, vmdesc);
> + ret = vmstate_save_state(f, vmsd, elm, vmdesc, &error_warn);
> if (ret) {
> error_report("%s: failed to save %s (%d)", field->name,
> vmsd->name, ret);
> diff --git a/migration/vmstate.c b/migration/vmstate.c
> index
> ef78a1e62ad92e9608de72d125da80ea496c8dd1..569e66ea983f833e6a0d651d2a751f34a64e8f5c
> 100644
> --- a/migration/vmstate.c
> +++ b/migration/vmstate.c
> @@ -403,12 +403,6 @@ bool vmstate_section_needed(const VMStateDescription
> *vmsd, void *opaque)
>
>
> int vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd,
> - void *opaque, JSONWriter *vmdesc_id)
> -{
> - return vmstate_save_state_v(f, vmsd, opaque, vmdesc_id,
> vmsd->version_id, NULL);
> -}
> -
> -int vmstate_save_state_with_err(QEMUFile *f, const VMStateDescription
> *vmsd,
> void *opaque, JSONWriter *vmdesc_id, Error **errp)
> {
> return vmstate_save_state_v(f, vmsd, opaque, vmdesc_id,
> vmsd->version_id, errp);
> @@ -530,7 +524,7 @@ static int vmstate_save_dispatch(QEMUFile *f,
>
> if (inner_field->flags & VMS_STRUCT) {
> ret = vmstate_save_state(f, inner_field->vmsd,
> - curr_elem, vmdesc_loop);
> + 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,
> @@ -539,6 +533,10 @@ static int vmstate_save_dispatch(QEMUFile *f,
> } else {
> ret = inner_field->info->put(f, curr_elem, size,
> inner_field,
> vmdesc_loop);
> + if (ret) {
> + error_setg(errp, "Save of field %s failed",
> + inner_field->name);
> + }
> }
>
> written_bytes = qemu_file_transferred(f) - old_offset;
> @@ -551,8 +549,8 @@ static int vmstate_save_dispatch(QEMUFile *f,
> }
>
> if (ret) {
> - error_setg(errp, "Save of field %s/%s failed",
> - vmsd->name, field->name);
> + error_prepend(errp, "Save of field %s/%s failed: ",
> + vmsd->name, field->name);
> ps_ret = post_save_dispatch(vmsd, opaque, &local_err);
> if (ps_ret) {
> ret = ps_ret;
> @@ -723,7 +721,7 @@ static int vmstate_subsection_save(QEMUFile *f, const
> VMStateDescription *vmsd,
> qemu_put_byte(f, len);
> qemu_put_buffer(f, (uint8_t *)vmsdsub->name, len);
> qemu_put_be32(f, vmsdsub->version_id);
> - ret = vmstate_save_state_with_err(f, vmsdsub, opaque, vmdesc,
> errp);
> + ret = vmstate_save_state(f, vmsdsub, opaque, vmdesc, errp);
> if (ret) {
> return ret;
> }
> diff --git a/tests/unit/test-vmstate.c b/tests/unit/test-vmstate.c
> index
> 807deb3531f3079864ac99567d4dece7122571dd..5f31ed4b6969c4ebf72b298f965bcbdc752ff87f
> 100644
> --- a/tests/unit/test-vmstate.c
> +++ b/tests/unit/test-vmstate.c
> @@ -69,7 +69,7 @@ static void save_vmstate(const VMStateDescription *desc,
> void *obj)
> QEMUFile *f = open_test_file(true);
>
> /* Save file with vmstate */
> - int ret = vmstate_save_state(f, desc, obj, NULL);
> + int ret = vmstate_save_state(f, desc, obj, NULL, &error_warn);
> g_assert(!ret);
> qemu_put_byte(f, QEMU_VM_EOF);
> g_assert(!qemu_file_get_error(f));
> @@ -429,7 +429,8 @@ static void test_save_noskip(void)
> QEMUFile *fsave = open_test_file(true);
> TestStruct obj = { .a = 1, .b = 2, .c = 3, .d = 4, .e = 5, .f = 6,
> .skip_c_e = false };
> - int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL);
> + int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL,
> + &error_warn);
> g_assert(!ret);
> g_assert(!qemu_file_get_error(fsave));
>
> @@ -451,7 +452,8 @@ static void test_save_skip(void)
> QEMUFile *fsave = open_test_file(true);
> TestStruct obj = { .a = 1, .b = 2, .c = 3, .d = 4, .e = 5, .f = 6,
> .skip_c_e = true };
> - int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL);
> + int ret = vmstate_save_state(fsave, &vmstate_skipping, &obj, NULL,
> + &error_warn);
> g_assert(!ret);
> g_assert(!qemu_file_get_error(fsave));
>
> diff --git a/ui/vdagent.c b/ui/vdagent.c
> index
> b9a22a689d9acfeafb862ae73308db6fbd52331e..e0fc7ff71468bfe66761385387653c742c375f05
> 100644
> --- a/ui/vdagent.c
> +++ b/ui/vdagent.c
> @@ -992,7 +992,8 @@ static int put_cbinfo(QEMUFile *f, void *pv, size_t
> size,
> }
> }
>
> - return vmstate_save_state(f, &vmstate_cbinfo_array, &cbinfo, vmdesc);
> + return vmstate_save_state(f, &vmstate_cbinfo_array, &cbinfo, vmdesc,
> + &error_warn);
> }
>
> static int get_cbinfo(QEMUFile *f, void *pv, size_t size,
>
> --
> 2.50.1
>
>
