Allow a notifier to be added for multiple migration modes.
To allow a notifier to appear on multiple per-node lists, use
a generic list type. We can no longer use NotifierWithReturnList,
because it shoe horns the notifier onto a single list.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
include/migration/misc.h | 12 ++++++++++
migration/migration.c | 60 +++++++++++++++++++++++++++++++++++++-----------
2 files changed, 59 insertions(+), 13 deletions(-)
diff --git a/include/migration/misc.h b/include/migration/misc.h
index a261f99..592b930 100644
--- a/include/migration/misc.h
+++ b/include/migration/misc.h
@@ -95,7 +95,19 @@ void migration_add_notifier(NotifierWithReturn *notify,
void migration_add_notifier_mode(NotifierWithReturn *notify,
MigrationNotifyFunc func, MigMode mode);
+/*
+ * Same as migration_add_notifier, but applies to all @mode in the argument
+ * list. The list is terminated by -1 or MIG_MODE_ALL. For the latter,
+ * the notifier is added for all modes.
+ */
+void migration_add_notifier_modes(NotifierWithReturn *notify,
+ MigrationNotifyFunc func, MigMode mode, ...);
+
+/*
+ * Remove a notifier from all modes.
+ */
void migration_remove_notifier(NotifierWithReturn *notify);
+
void migration_file_set_error(int ret, Error *err);
/* True if incoming migration entered POSTCOPY_INCOMING_DISCARD */
diff --git a/migration/migration.c b/migration/migration.c
index 49d1e7d..271c521 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -74,11 +74,7 @@
#define INMIGRATE_DEFAULT_EXIT_ON_ERROR true
-static NotifierWithReturnList migration_state_notifiers[] = {
- NOTIFIER_ELEM_INIT(migration_state_notifiers, MIG_MODE_NORMAL),
- NOTIFIER_ELEM_INIT(migration_state_notifiers, MIG_MODE_CPR_REBOOT),
- NOTIFIER_ELEM_INIT(migration_state_notifiers, MIG_MODE_CPR_TRANSFER),
-};
+static GSList *migration_state_notifiers[MIG_MODE__MAX];
/* Messages sent on the return path from destination to source */
enum mig_rp_message_type {
@@ -1666,23 +1662,51 @@ void migration_cancel(void)
}
}
+static int get_modes(MigMode mode, va_list ap);
+
+static void add_notifiers(NotifierWithReturn *notify, int modes)
+{
+ for (MigMode mode = 0; mode < MIG_MODE__MAX; mode++) {
+ if (modes & BIT(mode)) {
+ migration_state_notifiers[mode] =
+ g_slist_prepend(migration_state_notifiers[mode], notify);
+ }
+ }
+}
+
+void migration_add_notifier_modes(NotifierWithReturn *notify,
+ MigrationNotifyFunc func, MigMode mode, ...)
+{
+ int modes;
+ va_list ap;
+
+ va_start(ap, mode);
+ modes = get_modes(mode, ap);
+ va_end(ap);
+
+ notify->notify = (NotifierWithReturnFunc)func;
+ add_notifiers(notify, modes);
+}
+
void migration_add_notifier_mode(NotifierWithReturn *notify,
MigrationNotifyFunc func, MigMode mode)
{
- notify->notify = (NotifierWithReturnFunc)func;
- notifier_with_return_list_add(&migration_state_notifiers[mode], notify);
+ migration_add_notifier_modes(notify, func, mode, -1);
}
void migration_add_notifier(NotifierWithReturn *notify,
MigrationNotifyFunc func)
{
- migration_add_notifier_mode(notify, func, MIG_MODE_NORMAL);
+ migration_add_notifier_modes(notify, func, MIG_MODE_NORMAL, -1);
}
void migration_remove_notifier(NotifierWithReturn *notify)
{
if (notify->notify) {
- notifier_with_return_remove(notify);
+ for (MigMode mode = 0; mode < MIG_MODE__MAX; mode++) {
+ migration_blockers[mode] =
+ g_slist_remove(migration_state_notifiers[mode], notify);
+ }
notify->notify = NULL;
}
}
@@ -1692,13 +1716,23 @@ int migration_call_notifiers(MigrationState *s, MigrationEventType type,
{
MigMode mode = s->parameters.mode;
MigrationEvent e;
+ NotifierWithReturn *notifier;
+ GSList *elem, *next;
int ret;
e.type = type;
- ret = notifier_with_return_list_notify(&migration_state_notifiers[mode],
- &e, errp);
- assert(!ret || type == MIG_EVENT_PRECOPY_SETUP);
- return ret;
+
+ for (elem = migration_state_notifiers[mode]; elem; elem = next) {
+ next = elem->next;
+ notifier = (NotifierWithReturn *)elem->data;
+ ret = notifier->notify(notifier, &e, errp);
+ if (ret) {
+ assert(type == MIG_EVENT_PRECOPY_SETUP);
+ return ret;
+ }
+ }
+
+ return 0;
}
bool migration_has_failed(MigrationState *s)
--
1.8.3.1On Thu, Aug 14, 2025 at 10:17:15AM -0700, Steve Sistare wrote: > Allow a notifier to be added for multiple migration modes. > To allow a notifier to appear on multiple per-node lists, use > a generic list type. We can no longer use NotifierWithReturnList, > because it shoe horns the notifier onto a single list. > > Signed-off-by: Steve Sistare <steven.sistare@oracle.com> > --- > include/migration/misc.h | 12 ++++++++++ > migration/migration.c | 60 +++++++++++++++++++++++++++++++++++++----------- > 2 files changed, 59 insertions(+), 13 deletions(-) > > diff --git a/include/migration/misc.h b/include/migration/misc.h > index a261f99..592b930 100644 > --- a/include/migration/misc.h > +++ b/include/migration/misc.h > @@ -95,7 +95,19 @@ void migration_add_notifier(NotifierWithReturn *notify, > void migration_add_notifier_mode(NotifierWithReturn *notify, > MigrationNotifyFunc func, MigMode mode); > > +/* > + * Same as migration_add_notifier, but applies to all @mode in the argument > + * list. The list is terminated by -1 or MIG_MODE_ALL. For the latter, > + * the notifier is added for all modes. > + */ > +void migration_add_notifier_modes(NotifierWithReturn *notify, > + MigrationNotifyFunc func, MigMode mode, ...); Would it be more common to pass in a bitmask instead (rather than n parameters, plus a ending -1)? -- Peter Xu
On 9/9/2025 11:43 AM, Peter Xu wrote: > On Thu, Aug 14, 2025 at 10:17:15AM -0700, Steve Sistare wrote: >> Allow a notifier to be added for multiple migration modes. >> To allow a notifier to appear on multiple per-node lists, use >> a generic list type. We can no longer use NotifierWithReturnList, >> because it shoe horns the notifier onto a single list. >> >> Signed-off-by: Steve Sistare <steven.sistare@oracle.com> >> --- >> include/migration/misc.h | 12 ++++++++++ >> migration/migration.c | 60 +++++++++++++++++++++++++++++++++++++----------- >> 2 files changed, 59 insertions(+), 13 deletions(-) >> >> diff --git a/include/migration/misc.h b/include/migration/misc.h >> index a261f99..592b930 100644 >> --- a/include/migration/misc.h >> +++ b/include/migration/misc.h >> @@ -95,7 +95,19 @@ void migration_add_notifier(NotifierWithReturn *notify, >> void migration_add_notifier_mode(NotifierWithReturn *notify, >> MigrationNotifyFunc func, MigMode mode); >> >> +/* >> + * Same as migration_add_notifier, but applies to all @mode in the argument >> + * list. The list is terminated by -1 or MIG_MODE_ALL. For the latter, >> + * the notifier is added for all modes. >> + */ >> +void migration_add_notifier_modes(NotifierWithReturn *notify, >> + MigrationNotifyFunc func, MigMode mode, ...); > > Would it be more common to pass in a bitmask instead (rather than n > parameters, plus a ending -1)? Yes, but I defined it this way to avoid the common error of passing a bit position rather than a mask, eg: A = 10 B = 7 migration_add_notifier_modes(A | B) WRONG migration_add_notifier_modes(BIT(A) | BIT(B)) CORRECT and because IMO passing A, B is slightly more readable than passing BIT(A) | BIT(B). Note the blocker functions also take modes using varargs, so using a bitmask for the notifiers would give us two different representations. - Steve
Steve Sistare <steven.sistare@oracle.com> writes: > Allow a notifier to be added for multiple migration modes. > To allow a notifier to appear on multiple per-node lists, use > a generic list type. We can no longer use NotifierWithReturnList, > because it shoe horns the notifier onto a single list. > > Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Fabiano Rosas <farosas@suse.de>
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