util/qemu-timer: refactor deadline calculation for external timers

icount-based record/replay uses qemu_clock_deadline_ns_all to measure
the period until vCPU may be interrupted.
This function takes in account the virtual timers, because they belong
to the virtual devices that may generate interrupt request or affect
the virtual machine state.
However, there are a subset of virtual timers, that are marked with
'external' flag. These do not change the virtual machine state and
only based on virtual clock. Calculating the deadling using the external
timers breaks the determinism, because they do not belong to the replayed
part of the virtual machine.
This patch fixes the deadline calculation for this case by adding
new parameter for skipping the external timers when it is needed.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>

--

v2 changes:
 - added new parameter for timer attribute mask
Message-Id: <156404426682.18669.17014100602930969222.stgit@pasha-Precision-3630-Tower>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 6 insertions, 2 deletions

diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index 5bcab93..85bc6eb 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -62,13 +62,15 @@ typedef enum {
  * The following attributes are available:
  *
  * QEMU_TIMER_ATTR_EXTERNAL: drives external subsystem
+ * QEMU_TIMER_ATTR_ALL: mask for all existing attributes
  *
  * 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)
+#define QEMU_TIMER_ATTR_EXTERNAL ((int)BIT(0))
+#define QEMU_TIMER_ATTR_ALL      0xffffffff
 
 typedef struct QEMUTimerList QEMUTimerList;
 
@@ -177,6 +179,8 @@ bool qemu_clock_use_for_deadline(QEMUClockType type);
 /**
  * qemu_clock_deadline_ns_all:
  * @type: the clock type
+ * @attr_mask: mask for the timer attributes that are included
+ *             in deadline calculation
  *
  * Calculate the deadline across all timer lists associated
  * with a clock (as opposed to just the default one)
@@ -184,7 +188,7 @@ bool qemu_clock_use_for_deadline(QEMUClockType type);
  *
  * Returns: time until expiry in nanoseconds or -1
  */
-int64_t qemu_clock_deadline_ns_all(QEMUClockType type);
+int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask);
 
 /**
  * qemu_clock_get_main_loop_timerlist: