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-rw-r--r--include/qemu/timer.h10
-rw-r--r--slirp/ip6_icmp.c4
-rw-r--r--ui/input.c5
-rw-r--r--util/qemu-timer.c50
4 files changed, 58 insertions, 11 deletions
diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index 8ff1092f14..9f37c92bd1 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -60,9 +60,17 @@ typedef enum {
* Each attribute corresponds to one bit. Attributes modify the processing
* of timers when they fire.
*
- * No attributes defined currently.
+ * The following attributes are available:
+ *
+ * QEMU_TIMER_ATTR_EXTERNAL: drives external subsystem
+ *
+ * Timers with this attribute do not recorded in rr mode, therefore it could be
+ * used for the subsystems that operate outside the guest core. Applicable only
+ * with virtual clock type.
*/
+#define QEMU_TIMER_ATTR_EXTERNAL BIT(0)
+
typedef struct QEMUTimerList QEMUTimerList;
struct QEMUTimerListGroup {
diff --git a/slirp/ip6_icmp.c b/slirp/ip6_icmp.c
index ee333d05a2..cd1e0b9fe1 100644
--- a/slirp/ip6_icmp.c
+++ b/slirp/ip6_icmp.c
@@ -27,7 +27,9 @@ void icmp6_init(Slirp *slirp)
return;
}
- slirp->ra_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, ra_timer_handler, slirp);
+ slirp->ra_timer = timer_new_full(NULL, QEMU_CLOCK_VIRTUAL,
+ SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
+ ra_timer_handler, slirp);
timer_mod(slirp->ra_timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
}
diff --git a/ui/input.c b/ui/input.c
index 51b1019252..7c9a4109c4 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -448,8 +448,9 @@ void qemu_input_event_send_key_delay(uint32_t delay_ms)
}
if (!kbd_timer) {
- kbd_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, qemu_input_queue_process,
- &kbd_queue);
+ kbd_timer = timer_new_full(NULL, QEMU_CLOCK_VIRTUAL,
+ SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
+ qemu_input_queue_process, &kbd_queue);
}
if (queue_count < queue_limit) {
qemu_input_queue_delay(&kbd_queue, kbd_timer,
diff --git a/util/qemu-timer.c b/util/qemu-timer.c
index 04527a343f..1cc1b2f2c3 100644
--- a/util/qemu-timer.c
+++ b/util/qemu-timer.c
@@ -489,6 +489,7 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
bool progress = false;
QEMUTimerCB *cb;
void *opaque;
+ bool need_replay_checkpoint = false;
if (!atomic_read(&timer_list->active_timers)) {
return false;
@@ -504,8 +505,15 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
break;
default:
case QEMU_CLOCK_VIRTUAL:
- if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) {
- goto out;
+ if (replay_mode != REPLAY_MODE_NONE) {
+ /* Checkpoint for virtual clock is redundant in cases where
+ * it's being triggered with only non-EXTERNAL timers, because
+ * these timers don't change guest state directly.
+ * Since it has conditional dependence on specific timers, it is
+ * subject to race conditions and requires special handling.
+ * See below.
+ */
+ need_replay_checkpoint = true;
}
break;
case QEMU_CLOCK_HOST:
@@ -520,14 +528,39 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
break;
}
+ /*
+ * Extract expired timers from active timers list and and process them.
+ *
+ * In rr mode we need "filtered" checkpointing for virtual clock. The
+ * checkpoint must be recorded/replayed before processing any non-EXTERNAL timer,
+ * and that must only be done once since the clock value stays the same. Because
+ * non-EXTERNAL timers may appear in the timers list while it being processed,
+ * the checkpoint can be issued at a time until no timers are left and we are
+ * done".
+ */
current_time = qemu_clock_get_ns(timer_list->clock->type);
- for(;;) {
- qemu_mutex_lock(&timer_list->active_timers_lock);
- ts = timer_list->active_timers;
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ while ((ts = timer_list->active_timers)) {
if (!timer_expired_ns(ts, current_time)) {
- qemu_mutex_unlock(&timer_list->active_timers_lock);
+ /* No expired timers left. The checkpoint can be skipped
+ * if no timers fired or they were all external.
+ */
break;
}
+ if (need_replay_checkpoint
+ && !(ts->attributes & QEMU_TIMER_ATTR_EXTERNAL)) {
+ /* once we got here, checkpoint clock only once */
+ need_replay_checkpoint = false;
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
+ if (!replay_checkpoint(CHECKPOINT_CLOCK_VIRTUAL)) {
+ goto out;
+ }
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+ /* The lock was released; start over again in case the list was
+ * modified.
+ */
+ continue;
+ }
/* remove timer from the list before calling the callback */
timer_list->active_timers = ts->next;
@@ -535,12 +568,15 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
ts->expire_time = -1;
cb = ts->cb;
opaque = ts->opaque;
- qemu_mutex_unlock(&timer_list->active_timers_lock);
/* run the callback (the timer list can be modified) */
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
cb(opaque);
+ qemu_mutex_lock(&timer_list->active_timers_lock);
+
progress = true;
}
+ qemu_mutex_unlock(&timer_list->active_timers_lock);
out:
qemu_event_set(&timer_list->timers_done_ev);