Skip to content

Commit

Permalink
replay: pass raw icount value to replay_save_clock
Browse files Browse the repository at this point in the history
This avoids lock recursion when REPLAY_CLOCK is called inside the
timers spinlock.

Signed-off-by: Paolo Bonzini <[email protected]>
  • Loading branch information
bonzini committed Oct 19, 2018
1 parent 0c2ed83 commit 74c0b81
Show file tree
Hide file tree
Showing 7 changed files with 38 additions and 18 deletions.
4 changes: 2 additions & 2 deletions cpus.c
Original file line number Diff line number Diff line change
Expand Up @@ -509,8 +509,8 @@ static void icount_warp_rt(void)
seqlock_write_lock(&timers_state.vm_clock_seqlock,
&timers_state.vm_clock_lock);
if (runstate_is_running()) {
int64_t clock = REPLAY_CLOCK(REPLAY_CLOCK_VIRTUAL_RT,
cpu_get_clock_locked());
int64_t clock = REPLAY_CLOCK_LOCKED(REPLAY_CLOCK_VIRTUAL_RT,
cpu_get_clock_locked());
int64_t warp_delta;

warp_delta = clock - timers_state.vm_clock_warp_start;
Expand Down
10 changes: 8 additions & 2 deletions include/sysemu/replay.h
Original file line number Diff line number Diff line change
Expand Up @@ -100,14 +100,20 @@ bool replay_has_interrupt(void);
/* Processing clocks and other time sources */

/*! Save the specified clock */
int64_t replay_save_clock(ReplayClockKind kind, int64_t clock);
int64_t replay_save_clock(ReplayClockKind kind, int64_t clock,
int64_t raw_icount);
/*! Read the specified clock from the log or return cached data */
int64_t replay_read_clock(ReplayClockKind kind);
/*! Saves or reads the clock depending on the current replay mode. */
#define REPLAY_CLOCK(clock, value) \
(replay_mode == REPLAY_MODE_PLAY ? replay_read_clock((clock)) \
: replay_mode == REPLAY_MODE_RECORD \
? replay_save_clock((clock), (value)) \
? replay_save_clock((clock), (value), cpu_get_icount_raw()) \
: (value))
#define REPLAY_CLOCK_LOCKED(clock, value) \
(replay_mode == REPLAY_MODE_PLAY ? replay_read_clock((clock)) \
: replay_mode == REPLAY_MODE_RECORD \
? replay_save_clock((clock), (value), cpu_get_icount_raw_locked()) \
: (value))

/* Events */
Expand Down
25 changes: 15 additions & 10 deletions replay/replay-internal.c
Original file line number Diff line number Diff line change
Expand Up @@ -217,20 +217,25 @@ void replay_mutex_unlock(void)
}
}

void replay_advance_current_step(uint64_t current_step)
{
int diff = (int)(replay_get_current_step() - replay_state.current_step);

/* Time can only go forward */
assert(diff >= 0);

if (diff > 0) {
replay_put_event(EVENT_INSTRUCTION);
replay_put_dword(diff);
replay_state.current_step += diff;
}
}

/*! Saves cached instructions. */
void replay_save_instructions(void)
{
if (replay_file && replay_mode == REPLAY_MODE_RECORD) {
g_assert(replay_mutex_locked());
int diff = (int)(replay_get_current_step() - replay_state.current_step);

/* Time can only go forward */
assert(diff >= 0);

if (diff > 0) {
replay_put_event(EVENT_INSTRUCTION);
replay_put_dword(diff);
replay_state.current_step += diff;
}
replay_advance_current_step(replay_get_current_step());
}
}
2 changes: 2 additions & 0 deletions replay/replay-internal.h
Original file line number Diff line number Diff line change
Expand Up @@ -122,6 +122,8 @@ void replay_finish_event(void);
data_kind variable. */
void replay_fetch_data_kind(void);

/*! Advance replay_state.current_step to the specified value. */
void replay_advance_current_step(uint64_t current_step);
/*! Saves queued events (like instructions and sound). */
void replay_save_instructions(void);

Expand Down
8 changes: 5 additions & 3 deletions replay/replay-time.c
Original file line number Diff line number Diff line change
Expand Up @@ -15,13 +15,15 @@
#include "replay-internal.h"
#include "qemu/error-report.h"

int64_t replay_save_clock(ReplayClockKind kind, int64_t clock)
int64_t replay_save_clock(ReplayClockKind kind, int64_t clock, int64_t raw_icount)
{

if (replay_file) {
g_assert(replay_mutex_locked());

replay_save_instructions();
/* Due to the caller's locking requirements we get the icount from it
* instead of using replay_save_instructions().
*/
replay_advance_current_step(raw_icount);
replay_put_event(EVENT_CLOCK + kind);
replay_put_qword(clock);
}
Expand Down
5 changes: 5 additions & 0 deletions stubs/cpu-get-icount.c
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,11 @@ int64_t cpu_get_icount(void)
abort();
}

int64_t cpu_get_icount_raw(void)
{
abort();
}

void qemu_timer_notify_cb(void *opaque, QEMUClockType type)
{
qemu_notify_event();
Expand Down
2 changes: 1 addition & 1 deletion stubs/replay.c
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@

ReplayMode replay_mode;

int64_t replay_save_clock(unsigned int kind, int64_t clock)
int64_t replay_save_clock(unsigned int kind, int64_t clock, int64_t raw_icount)
{
abort();
return 0;
Expand Down

0 comments on commit 74c0b81

Please sign in to comment.