We currently create a new announcement timer every time
qemu_announce_self() is called. Since this is now a qmp
command, this can lead to abuse. Limit the number of
timers that are created. Give QMP interface and migration
process 1 timer each. This way, QMP can't abuse the
announce_self mechanism.
Signed-off-by: Vladislav Yasevich <vyase...@redhat.com>
---
include/migration/vmstate.h | 1 +
include/sysemu/sysemu.h | 9 ++++++++-
migration/migration.c | 2 +-
migration/savevm.c | 24 +++++++++++++++++++-----
4 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/include/migration/vmstate.h b/include/migration/vmstate.h
index f8aed9b..689b685 100644
--- a/include/migration/vmstate.h
+++ b/include/migration/vmstate.h
@@ -1057,6 +1057,7 @@ void vmstate_register_ram_global(struct MemoryRegion
*memory);
typedef struct AnnounceTimer {
QEMUTimer *tm;
+ struct AnnounceTimer **entry;
AnnounceParameters params;
QEMUClockType type;
int round;
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index 2ef1687..85a2af1 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -78,14 +78,21 @@ void qemu_remove_machine_init_done_notifier(Notifier
*notify);
int save_vmstate(const char *name, Error **errp);
int load_vmstate(const char *name, Error **errp);
+typedef enum AnnounceType {
+ QEMU_ANNOUNCE_MIGRATION,
+ QEMU_ANNOUNCE_USER,
+ QEMU_ANNOUNCE__MAX,
+} AnnounceType;
+
AnnounceParameters *qemu_get_announce_params(void);
void qemu_fill_announce_parameters(AnnounceParameters **to,
AnnounceParameters *from);
+
bool qemu_validate_announce_parameters(AnnounceParameters *params,
Error **errp);
void qemu_set_announce_parameters(AnnounceParameters *announce_params,
AnnounceParameters *params);
-void qemu_announce_self(AnnounceParameters *params);
+void qemu_announce_self(AnnounceParameters *params, AnnounceType type);
/* Subcommands for QEMU_VM_COMMAND */
enum qemu_vm_cmd {
diff --git a/migration/migration.c b/migration/migration.c
index 987c1cf..724fc40 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -345,7 +345,7 @@ static void process_incoming_migration_bh(void *opaque)
* This must happen after all error conditions are dealt with and
* we're sure the VM is going to be running on this host.
*/
- qemu_announce_self(qemu_get_announce_params());
+ qemu_announce_self(qemu_get_announce_params(), QEMU_ANNOUNCE_MIGRATION);
/* If global state section was not received or we are in running
state, we need to obey autostart. Any other state is set with
diff --git a/migration/savevm.c b/migration/savevm.c
index b55ce6a..dcba8bd 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -218,6 +218,8 @@ static void qemu_announce_self_iter(NICState *nic, void
*opaque)
}
}
+AnnounceTimer *announce_timers[QEMU_ANNOUNCE__MAX];
+
static void qemu_announce_self_once(void *opaque)
{
AnnounceTimer *timer = (AnnounceTimer *)opaque;
@@ -228,6 +230,7 @@ static void qemu_announce_self_once(void *opaque)
timer_mod(timer->tm, qemu_clock_get_ms(timer->type) +
self_announce_delay(timer));
} else {
+ *(timer->entry) = NULL;
timer_del(timer->tm);
timer_free(timer->tm);
g_free(timer);
@@ -256,12 +259,23 @@ AnnounceTimer
*qemu_announce_timer_create(AnnounceParameters *params,
return timer;
}
-void qemu_announce_self(AnnounceParameters *params)
+void qemu_announce_self(AnnounceParameters *params, AnnounceType type)
{
AnnounceTimer *timer;
- timer = qemu_announce_timer_create(params, QEMU_CLOCK_REALTIME,
- qemu_announce_self_once);
+ timer = announce_timers[type];
+ if (!timer) {
+ timer = qemu_announce_timer_create(params, QEMU_CLOCK_REALTIME,
+ qemu_announce_self_once);
+ announce_timers[type] = timer;
+ timer->entry = &announce_timers[type];
+ } else {
+ /* For now, don't do anything. If we want to reset the timer,
+ * we'll need to add locking to each announce timer to prevent
+ * races between timeout handling and a reset.
+ */
+ return;
+ }
qemu_announce_self_once(timer);
}
@@ -276,7 +290,7 @@ void qmp_announce_self(bool has_params, AnnounceParameters
*params,
if (has_params)
qemu_set_announce_parameters(&announce_params, params);
- qemu_announce_self(&announce_params);
+ qemu_announce_self(&announce_params, QEMU_ANNOUNCE_USER);
}
/***********************************************************/
@@ -1750,7 +1764,7 @@ static void loadvm_postcopy_handle_run_bh(void *opaque)
*/
cpu_synchronize_all_post_init();
- qemu_announce_self(qemu_get_announce_params());
+ qemu_announce_self(qemu_get_announce_params(), QEMU_ANNOUNCE_MIGRATION);
/* Make sure all file formats flush their mutable metadata.
* If we get an error here, just don't restart the VM yet. */
--
2.7.4
