replay: save prior value of the host clock

This patch adds saving/restoring of the host clock field 'last'.
It is used in host clock calculation and therefore clock may
become incorrect when using restored vmstate.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20180227095226.1060.50975.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>

diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index 3b5a54b014377c51c89595c113016cd5ebb54c3f..39ea907e65f0957b227cd83c5cac4d72a6ab2b39 100644 (file)
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -251,6 +251,20 @@ bool qemu_clock_run_timers(QEMUClockType type);
  */
 bool qemu_clock_run_all_timers(void);
 
+/**
+ * qemu_clock_get_last:
+ *
+ * Returns last clock query time.
+ */
+uint64_t qemu_clock_get_last(QEMUClockType type);
+/**
+ * qemu_clock_set_last:
+ *
+ * Sets last clock query time.
+ */
+void qemu_clock_set_last(QEMUClockType type, uint64_t last);
+
+
 /*
  * QEMUTimerList
  */

diff --git a/replay/replay-internal.h b/replay/replay-internal.h
index 3ebb19912a7841a27f468555960ab535a95e4abe..be96d7e879caa78ba5fa46071ff2aeee6c84b16d 100644 (file)
--- a/replay/replay-internal.h
+++ b/replay/replay-internal.h
@@ -78,6 +78,8 @@ typedef struct ReplayState {
         This counter is global, because requests from different
         block devices should not get overlapping ids. */
     uint64_t block_request_id;
+    /*! Prior value of the host clock */
+    uint64_t host_clock_last;
 } ReplayState;
 extern ReplayState replay_state;
 

diff --git a/replay/replay-snapshot.c b/replay/replay-snapshot.c
index 7075986ab52456cdb99010da6e535a94be2fe759..e0b2204765cc4dd2f31c17ae0ff755a3093bdde9 100644 (file)
--- a/replay/replay-snapshot.c
+++ b/replay/replay-snapshot.c
@@ -25,6 +25,7 @@ static int replay_pre_save(void *opaque)
 {
     ReplayState *state = opaque;
     state->file_offset = ftell(replay_file);
+    state->host_clock_last = qemu_clock_get_last(QEMU_CLOCK_HOST);
 
     return 0;
 }
@@ -33,6 +34,7 @@ static int replay_post_load(void *opaque, int version_id)
 {
     ReplayState *state = opaque;
     fseek(replay_file, state->file_offset, SEEK_SET);
+    qemu_clock_set_last(QEMU_CLOCK_HOST, state->host_clock_last);
     /* If this was a vmstate, saved in recording mode,
        we need to initialize replay data fields. */
     replay_fetch_data_kind();
@@ -54,6 +56,7 @@ static const VMStateDescription vmstate_replay = {
         VMSTATE_UINT32(has_unread_data, ReplayState),
         VMSTATE_UINT64(file_offset, ReplayState),
         VMSTATE_UINT64(block_request_id, ReplayState),
+        VMSTATE_UINT64(host_clock_last, ReplayState),
         VMSTATE_END_OF_LIST()
     },
 };

diff --git a/util/qemu-timer.c b/util/qemu-timer.c
index 82d56507a2bdc2416667c7d863798e91298904af..2ed1bf2778a40f12b51e58124e57a5a236fde0e4 100644 (file)
--- a/util/qemu-timer.c
+++ b/util/qemu-timer.c
@@ -622,6 +622,18 @@ int64_t qemu_clock_get_ns(QEMUClockType type)
     }
 }
 
+uint64_t qemu_clock_get_last(QEMUClockType type)
+{
+    QEMUClock *clock = qemu_clock_ptr(type);
+    return clock->last;
+}
+
+void qemu_clock_set_last(QEMUClockType type, uint64_t last)
+{
+    QEMUClock *clock = qemu_clock_ptr(type);
+    clock->last = last;
+}
+
 void qemu_clock_register_reset_notifier(QEMUClockType type,
                                         Notifier *notifier)
 {