qemu/replay/replay-time.c
Pavel Dovgalyuk 366a85e4bb replay: fix icount request when replaying clock access
Record/replay provides REPLAY_CLOCK_LOCKED macro to access
the clock when vm_clock_seqlock is locked. This macro is
needed because replay internals operate icount. In locked case
replay use icount_get_raw_locked for icount request, which prevents
excess locking which leads to deadlock. But previously only
record code used *_locked function and replay did not.
Therefore sometimes clock access lead to deadlocks.
This patch fixes clock access for replay too and uses *_locked
icount access function.

Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Message-Id: <161347990483.1313189.8371838968343494161.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-02-16 17:15:39 +01:00

62 lines
1.5 KiB
C

/*
* replay-time.c
*
* Copyright (c) 2010-2015 Institute for System Programming
* of the Russian Academy of Sciences.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "sysemu/replay.h"
#include "replay-internal.h"
#include "qemu/error-report.h"
int64_t replay_save_clock(ReplayClockKind kind, int64_t clock,
int64_t raw_icount)
{
g_assert(replay_file);
g_assert(replay_mutex_locked());
/*
* Due to the caller's locking requirements we get the icount from it
* instead of using replay_save_instructions().
*/
replay_advance_current_icount(raw_icount);
replay_put_event(EVENT_CLOCK + kind);
replay_put_qword(clock);
return clock;
}
void replay_read_next_clock(ReplayClockKind kind)
{
unsigned int read_kind = replay_state.data_kind - EVENT_CLOCK;
assert(read_kind == kind);
int64_t clock = replay_get_qword();
replay_check_error();
replay_finish_event();
replay_state.cached_clock[read_kind] = clock;
}
/*! Reads next clock event from the input. */
int64_t replay_read_clock(ReplayClockKind kind, int64_t raw_icount)
{
int64_t ret;
g_assert(replay_file && replay_mutex_locked());
replay_advance_current_icount(raw_icount);
if (replay_next_event_is(EVENT_CLOCK + kind)) {
replay_read_next_clock(kind);
}
ret = replay_state.cached_clock[kind];
return ret;
}