On 2025/07/31 22:20, 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 qemu_loadvm_state_main() must report an error
in errp, in case of failure.
loadvm_process_command also sets the errp object explicitly.
Reviewed-by: Daniel P. Berrangé <[email protected]>
Signed-off-by: Arun Menon <[email protected]>
---
migration/colo.c | 5 +++--
migration/savevm.c | 27 ++++++++++++++++-----------
migration/savevm.h | 3 ++-
3 files changed, 21 insertions(+), 14 deletions(-)
diff --git a/migration/colo.c b/migration/colo.c
index
981bd4bf9ced8b45b4c5d494acae119a174ee974..529794dfc8d943b8ba3a25391ee2132c0c3f312e
100644
--- a/migration/colo.c
+++ b/migration/colo.c
@@ -659,6 +659,7 @@ void migrate_start_colo_process(MigrationState *s)
static void colo_incoming_process_checkpoint(MigrationIncomingState *mis,
QEMUFile *fb, QIOChannelBuffer *bioc, Error **errp)
{
+ ERRP_GUARD();
uint64_t total_size;
uint64_t value;
Error *local_err = NULL;
@@ -686,11 +687,11 @@ static void
colo_incoming_process_checkpoint(MigrationIncomingState *mis,
bql_lock();
cpu_synchronize_all_states();
- ret = qemu_loadvm_state_main(mis->from_src_file, mis);
+ ret = qemu_loadvm_state_main(mis->from_src_file, mis, errp);
bql_unlock();
if (ret < 0) {
- error_setg(errp, "Load VM's live state (ram) error");
+ error_prepend(errp, "Load VM's live state (ram) error: ");
return;
}
diff --git a/migration/savevm.c b/migration/savevm.c
index
e885f1724f223771d60081fea199320abc549d2f..f5903995edd2b4c4f6c1a214c7126d831f10c9f1
100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -2111,7 +2111,7 @@ static void *postcopy_ram_listen_thread(void *opaque)
qemu_file_set_blocking(f, true);
/* TODO: sanity check that only postcopiable data will be loaded here */
- load_res = qemu_loadvm_state_main(f, mis);
+ load_res = qemu_loadvm_state_main(f, mis, NULL);
/*
* This is tricky, but, mis->from_src_file can change after it
@@ -2412,6 +2412,7 @@ static void
loadvm_postcopy_handle_resume(MigrationIncomingState *mis)
*/
static int loadvm_handle_cmd_packaged(MigrationIncomingState *mis, Error
**errp)
{
+ ERRP_GUARD();
int ret;
size_t length;
QIOChannelBuffer *bioc;
@@ -2461,9 +2462,9 @@ static int
loadvm_handle_cmd_packaged(MigrationIncomingState *mis, Error **errp)
qemu_coroutine_yield();
} while (1);
- ret = qemu_loadvm_state_main(packf, mis);
+ ret = qemu_loadvm_state_main(packf, mis, errp);
if (ret < 0) {
- error_setg(errp, "VM state load failed: %d", ret);
+ error_prepend(errp, "Loading VM state failed: %d: ", ret);
}
trace_loadvm_handle_cmd_packaged_main(ret);
qemu_fclose(packf);
@@ -3066,8 +3067,10 @@ static bool
postcopy_pause_incoming(MigrationIncomingState *mis)
return true;
}
-int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis)
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis,
+ Error **errp)
{
+ ERRP_GUARD();
uint8_t section_type;
int ret = 0;
@@ -3075,8 +3078,10 @@ retry:
while (true) {
section_type = qemu_get_byte(f);
- ret = qemu_file_get_error_obj_any(f, mis->postcopy_qemufile_dst, NULL);
+ ret = qemu_file_get_error_obj_any(f, mis->postcopy_qemufile_dst, errp);
if (ret) {
+ error_prepend(errp, "Failed to load device state section ID: %d: ",
+ ret);
I noticed this is after the "retry" label; errp already contains an
error when retried so the error needs to be properly reported and freed.
break;
}
@@ -3084,20 +3089,20 @@ retry:
switch (section_type) {
case QEMU_VM_SECTION_START:
case QEMU_VM_SECTION_FULL:
- ret = qemu_loadvm_section_start_full(f, section_type, NULL);
+ ret = qemu_loadvm_section_start_full(f, section_type, errp);
if (ret < 0) {
goto out;
}
break;
case QEMU_VM_SECTION_PART:
case QEMU_VM_SECTION_END:
- ret = qemu_loadvm_section_part_end(f, section_type, NULL);
+ ret = qemu_loadvm_section_part_end(f, section_type, errp);
if (ret < 0) {
goto out;
}
break;
case QEMU_VM_COMMAND:
- ret = loadvm_process_command(f, NULL);
+ ret = loadvm_process_command(f, errp);
trace_qemu_loadvm_state_section_command(ret);
if ((ret < 0) || (ret == LOADVM_QUIT)) {
goto out;
@@ -3107,7 +3112,7 @@ retry:
/* This is the end of migration */
goto out;
default:
- error_report("Unknown savevm section type %d", section_type);
+ error_setg(errp, "Unknown savevm section type %d", section_type);
ret = -EINVAL;
goto out;
}
@@ -3171,7 +3176,7 @@ int qemu_loadvm_state(QEMUFile *f)
cpu_synchronize_all_pre_loadvm();
- ret = qemu_loadvm_state_main(f, mis);
+ ret = qemu_loadvm_state_main(f, mis, NULL);
qemu_event_set(&mis->main_thread_load_event);
trace_qemu_loadvm_state_post_main(ret);
@@ -3245,7 +3250,7 @@ int qemu_load_device_state(QEMUFile *f)
int ret;
/* Load QEMU_VM_SECTION_FULL section */
- ret = qemu_loadvm_state_main(f, mis);
+ ret = qemu_loadvm_state_main(f, mis, NULL);
if (ret < 0) {
error_report("Failed to load device state: %d", ret);
return ret;
diff --git a/migration/savevm.h b/migration/savevm.h
index
2d5e9c716686f06720325e82fe90c75335ced1de..fd7419e6ff90062970ed246b3ea71e6d49a6e372
100644
--- a/migration/savevm.h
+++ b/migration/savevm.h
@@ -66,7 +66,8 @@ int qemu_save_device_state(QEMUFile *f);
int qemu_loadvm_state(QEMUFile *f);
void qemu_loadvm_state_cleanup(MigrationIncomingState *mis);
-int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis);
+int qemu_loadvm_state_main(QEMUFile *f, MigrationIncomingState *mis,
+ Error **errp);
int qemu_load_device_state(QEMUFile *f);
int qemu_loadvm_approve_switchover(void);
int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
