@samitouri / QOSamiQemu / commits / a0248548ca

monitor: protect qemu_chr_fe_accept_input with monitor lock

The monitor_accept_input API is called from a bottom half, and will invoke qemu_chr_fe_accept_input(). When a following patch introduces the ability to delete monitors, it will be neccesary to delete the bottom half. Protecting the call to qemu_chr_fe_accept_input with the monitor lock will allow for synchronization with the deletion process. Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> [DB: extracted from a larger commit and refactored to apply to the new monitor class structure] Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Tested-by: Peter Krempa <pkrempa@redhat.com> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-ID: <20260706135824.2623960-27-berrange@redhat.com> Signed-off-by: Markus Armbruster <armbru@redhat.com>

Christian Brauner committed Jul 6, 2026 at 14:58 UTC a0248548ca784ef14a6d3bc01e95d5e8a4bdc559

3 files changed +12 -5

monitor/hmp.c

@@ -116,9 +116,11 @@ static void monitor_hmp_accept_input(Monitor *mon)

116 MonitorHMP *hmp = MONITOR_HMP(mon);

117 assert(hmp->rs);

118 readline_restart(hmp->rs);

119 + qemu_chr_fe_accept_input(&mon->chr);

120 qemu_mutex_unlock(&mon->mon_lock);

121 readline_show_prompt(hmp->rs);

122 } else {

123 + qemu_chr_fe_accept_input(&mon->chr);

124 qemu_mutex_unlock(&mon->mon_lock);

125 }

126 }

monitor/monitor.c

+1 -5

@@ -562,11 +562,7 @@ static void monitor_accept_input(void *opaque)

562 Monitor *mon = opaque;

563 MonitorClass *cls = MONITOR_GET_CLASS(mon);

564

565 - if (cls->accept_input) {

566 - cls->accept_input(mon);

567 - }

568 -

569 - qemu_chr_fe_accept_input(&mon->chr);

565 + cls->accept_input(mon);

566 }

567

568 void monitor_resume(Monitor *mon)

monitor/qmp.c

@@ -107,6 +107,7 @@ static void monitor_qmp_emit_event(Monitor *mon, QAPIEvent event, QDict *qdict);

107 static bool monitor_qmp_requires_iothread(const Monitor *mon);

108 static void monitor_qmp_complete(UserCreatable *uc, Error **errp);

109 static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp);

110 +static void monitor_qmp_accept_input(Monitor *mon);

111

112 static void monitor_qmp_class_init(ObjectClass *cls, const void *data)

113 {

@@ -119,6 +120,7 @@ static void monitor_qmp_class_init(ObjectClass *cls, const void *data)

120

121 moncls->emit_event = monitor_qmp_emit_event;

122 moncls->requires_iothread = monitor_qmp_requires_iothread;

123 + moncls->accept_input = monitor_qmp_accept_input;

124

125 ucc->complete = monitor_qmp_complete;

126 ucc->prepare_delete = monitor_qmp_prepare_delete;

@@ -665,3 +667,10 @@ static bool monitor_qmp_prepare_delete(UserCreatable *uc, Error **errp)

667 error_setg(errp, "Deleting QMP monitors is not supported");

668 return false;

669 }

670 +

671 +static void monitor_qmp_accept_input(Monitor *mon)

672 +{

673 + WITH_QEMU_LOCK_GUARD(&mon->mon_lock) {

674 + qemu_chr_fe_accept_input(&mon->chr);

675 + }

676 +}