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authorPavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>2018-09-12 11:20:02 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2018-10-02 19:08:58 +0200
commit87f4fe7653baf55b5c2f2753fe6003f473c07342 (patch)
tree1bfc1d1f1dfe334f259941eceb656667ec0c8044
parentbb3d7702e8dd0fd84c9496e226b46ce964b76e13 (diff)
timer: introduce new virtual clock
Slirp and VNC modules use virtual clock for processing some events that are related to the guest execution speed. But virtual clock-related events are consideres to be deterministic and are recorded/replayed by icount mechanism. But slirp and VNC lie outside the recorded guest core (which includes CPU and peripherals). Therefore slirp and VNC are external for the guest, but should work at guest speed. This patch introduces new virtual clock which can be used for external subsystems for running timers that are synchronized with the guest. Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru> Message-Id: <20180912082002.3228.82417.stgit@pasha-VirtualBox> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--include/qemu/timer.h9
-rw-r--r--util/qemu-timer.c2
2 files changed, 11 insertions, 0 deletions
diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index 39ea907e65..a005ed2692 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -42,6 +42,14 @@
* In icount mode, this clock counts nanoseconds while the virtual
* machine is running. It is used to increase @QEMU_CLOCK_VIRTUAL
* while the CPUs are sleeping and thus not executing instructions.
+ *
+ * @QEMU_CLOCK_VIRTUAL_EXT: virtual clock for external subsystems
+ *
+ * The virtual clock only runs during the emulation. It stops
+ * when the virtual machine is stopped. The timers for this clock
+ * do not recorded in rr mode, therefore this clock could be used
+ * for the subsystems that operate outside the guest core.
+ *
*/
typedef enum {
@@ -49,6 +57,7 @@ typedef enum {
QEMU_CLOCK_VIRTUAL = 1,
QEMU_CLOCK_HOST = 2,
QEMU_CLOCK_VIRTUAL_RT = 3,
+ QEMU_CLOCK_VIRTUAL_EXT = 4,
QEMU_CLOCK_MAX
} QEMUClockType;
diff --git a/util/qemu-timer.c b/util/qemu-timer.c
index 86bfe84037..eb60d8f73a 100644
--- a/util/qemu-timer.c
+++ b/util/qemu-timer.c
@@ -496,6 +496,7 @@ bool timerlist_run_timers(QEMUTimerList *timer_list)
switch (timer_list->clock->type) {
case QEMU_CLOCK_REALTIME:
+ case QEMU_CLOCK_VIRTUAL_EXT:
break;
default:
case QEMU_CLOCK_VIRTUAL:
@@ -597,6 +598,7 @@ int64_t qemu_clock_get_ns(QEMUClockType type)
return get_clock();
default:
case QEMU_CLOCK_VIRTUAL:
+ case QEMU_CLOCK_VIRTUAL_EXT:
if (use_icount) {
return cpu_get_icount();
} else {