migration: vmstate_save/load_state(): refactor tracing errors
To simplify further changes (convertion to bool+errp APIs), let's rework some error paths: - get rid of int ret in traces, as we are moving to bool+errp APIs - split traces to _fail / _success (seems better than add boolean result to the message). - prefer short error paths (return immediately on error) - around trace_vmstate_load_field_error(), do not call qemu_file_set_error(), if the erroc comes from qemu_file_get_error() Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru> Reviewed-by: Peter Xu <peterx@redhat.com> Link: https://lore.kernel.org/qemu-devel/20260304212303.667141-6-vsementsov@yandex-team.ru Signed-off-by: Fabiano Rosas <farosas@suse.de>
Vladimir Sementsov-Ogievskiy committed
Mar 5, 2026 at 00:22 UTC
1417266b1bcee80af618e7d0ab49187ff784dc69
2 files changed
+19
-12
migration/trace-events
+4
-2
@@ -56,13 +56,15 @@ postcopy_page_req_sync(void *host_addr) "sync page req %p"
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# vmstate.c
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vmstate_load_field_error(const char *field, int ret) "field \"%s\" load failed, ret = %d"
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vmstate_load_state(const char *name, int version_id) "%s v%d"
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-vmstate_load_state_end(const char *name, const char *reason, int val) "%s %s/%d"
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+vmstate_load_state_fail(const char *name, const char *reason) "%s %s"
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+vmstate_load_state_success(const char *name) "%s"
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vmstate_load_state_field(const char *name, const char *field, bool exists) "%s:%s exists=%d"
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vmstate_n_elems(const char *name, int n_elems) "%s: %d"
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vmstate_subsection_load(const char *parent) "%s"
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vmstate_subsection_load_bad(const char *parent, const char *sub, const char *sub2) "%s: %s/%s"
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vmstate_subsection_load_good(const char *parent) "%s"
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-vmstate_save_state_pre_save_res(const char *name, int res) "%s/%d"
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+vmstate_save_state_pre_save_fail(const char *name) "%s"
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+vmstate_save_state_pre_save_success(const char *name) "%s"
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vmstate_save_state_loop(const char *name, const char *field, int n_elems) "%s/%s[%d]"
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vmstate_save_state_top(const char *idstr) "%s"
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vmstate_subsection_save_loop(const char *name, const char *sub) "%s/%s"
migration/vmstate.c
+15
-10
@@ -144,7 +144,7 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
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error_setg(errp, "%s: incoming version_id %d is too new "
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"for local version_id %d",
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vmsd->name, version_id, vmsd->version_id);
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- trace_vmstate_load_state_end(vmsd->name, "too new", -EINVAL);
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+ trace_vmstate_load_state_fail(vmsd->name, "too new");
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return -EINVAL;
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}
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@@ -152,7 +152,7 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
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error_setg(errp, "%s: incoming version_id %d is too old "
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"for local minimum version_id %d",
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vmsd->name, version_id, vmsd->minimum_version_id);
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- trace_vmstate_load_state_end(vmsd->name, "too old", -EINVAL);
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+ trace_vmstate_load_state_fail(vmsd->name, "too old");
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return -EINVAL;
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}
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@@ -240,10 +240,10 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
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error_setg(errp,
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"Failed to load %s state: stream error: %d",
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vmsd->name, ret);
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+ trace_vmstate_load_field_error(field->name, ret);
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+ return ret;
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}
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- }
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-
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- if (ret < 0) {
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+ } else {
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qemu_file_set_error(f, ret);
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trace_vmstate_load_field_error(field->name, ret);
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return ret;
@@ -269,7 +269,8 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
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error_prepend(errp, "post load hook failed for: %s, version_id: "
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"%d, minimum_version: %d: ", vmsd->name,
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vmsd->version_id, vmsd->minimum_version_id);
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- ret = -EINVAL;
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+ trace_vmstate_load_state_fail(vmsd->name, "post-load");
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+ return -EINVAL;
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}
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} else if (vmsd->post_load) {
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ret = vmsd->post_load(opaque, version_id);
@@ -279,12 +280,14 @@ int vmstate_load_state(QEMUFile *f, const VMStateDescription *vmsd,
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"minimum_version: %d, ret: %d",
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vmsd->name, vmsd->version_id, vmsd->minimum_version_id,
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ret);
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+ trace_vmstate_load_state_fail(vmsd->name, "post-load");
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+ return ret;
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}
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}
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- trace_vmstate_load_state_end(vmsd->name, "end", ret);
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+ trace_vmstate_load_state_success(vmsd->name);
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- return ret;
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+ return 0;
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}
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static int vmfield_name_num(const VMStateField *start,
@@ -444,20 +447,22 @@ static int vmstate_save_state_v(QEMUFile *f, const VMStateDescription *vmsd,
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if (vmsd->pre_save_errp) {
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ret = vmsd->pre_save_errp(opaque, errp) ? 0 : -EINVAL;
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- trace_vmstate_save_state_pre_save_res(vmsd->name, ret);
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if (ret < 0) {
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error_prepend(errp, "pre-save for %s failed: ", vmsd->name);
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+ trace_vmstate_save_state_pre_save_fail(vmsd->name);
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return ret;
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}
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} else if (vmsd->pre_save) {
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ret = vmsd->pre_save(opaque);
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- trace_vmstate_save_state_pre_save_res(vmsd->name, ret);
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if (ret) {
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error_setg(errp, "pre-save failed: %s", vmsd->name);
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+ trace_vmstate_save_state_pre_save_fail(vmsd->name);
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return ret;
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}
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}
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+ trace_vmstate_save_state_pre_save_success(vmsd->name);
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+
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if (vmdesc) {
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json_writer_str(vmdesc, "vmsd_name", vmsd->name);
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json_writer_int64(vmdesc, "version", version_id);