qemu-patch-raspberry4/replay/replay-events.c
Pavel Dovgalyuk 33577b47c6 replay: character devices
This patch implements record and replay of character devices.
It records chardevs communication in replay mode. Recorded information
include data read from backend and counter of bytes written
from frontend to backend to preserve frontend internal state.
If character device was configured through the command line in record mode,
then in replay mode it should be also added to command line. Backend of
the character device could be changed in replay mode.
Replaying of devices that perform ioctl and get_msgfd operations is not
supported.
gdbstub which also acts as a backend is not recorded to allow controlling
the replaying through gdb. Monitor backends are also not recorded.

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
Message-Id: <20160314074436.4980.83856.stgit@PASHA-ISP>
[Add stubs. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-03-15 18:23:40 +01:00

292 lines
7.1 KiB
C

/*
* replay-events.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 "qemu-common.h"
#include "qemu/error-report.h"
#include "sysemu/replay.h"
#include "replay-internal.h"
#include "block/aio.h"
#include "ui/input.h"
typedef struct Event {
ReplayAsyncEventKind event_kind;
void *opaque;
void *opaque2;
uint64_t id;
QTAILQ_ENTRY(Event) events;
} Event;
static QTAILQ_HEAD(, Event) events_list = QTAILQ_HEAD_INITIALIZER(events_list);
static unsigned int read_event_kind = -1;
static uint64_t read_id = -1;
static int read_checkpoint = -1;
static bool events_enabled;
/* Functions */
static void replay_run_event(Event *event)
{
switch (event->event_kind) {
case REPLAY_ASYNC_EVENT_BH:
aio_bh_call(event->opaque);
break;
case REPLAY_ASYNC_EVENT_INPUT:
qemu_input_event_send_impl(NULL, (InputEvent *)event->opaque);
qapi_free_InputEvent((InputEvent *)event->opaque);
break;
case REPLAY_ASYNC_EVENT_INPUT_SYNC:
qemu_input_event_sync_impl();
break;
case REPLAY_ASYNC_EVENT_CHAR_READ:
replay_event_char_read_run(event->opaque);
break;
default:
error_report("Replay: invalid async event ID (%d) in the queue",
event->event_kind);
exit(1);
break;
}
}
void replay_enable_events(void)
{
events_enabled = true;
}
bool replay_has_events(void)
{
return !QTAILQ_EMPTY(&events_list);
}
void replay_flush_events(void)
{
replay_mutex_lock();
while (!QTAILQ_EMPTY(&events_list)) {
Event *event = QTAILQ_FIRST(&events_list);
replay_mutex_unlock();
replay_run_event(event);
replay_mutex_lock();
QTAILQ_REMOVE(&events_list, event, events);
g_free(event);
}
replay_mutex_unlock();
}
void replay_disable_events(void)
{
if (replay_mode != REPLAY_MODE_NONE) {
events_enabled = false;
/* Flush events queue before waiting of completion */
replay_flush_events();
}
}
void replay_clear_events(void)
{
replay_mutex_lock();
while (!QTAILQ_EMPTY(&events_list)) {
Event *event = QTAILQ_FIRST(&events_list);
QTAILQ_REMOVE(&events_list, event, events);
g_free(event);
}
replay_mutex_unlock();
}
/*! Adds specified async event to the queue */
void replay_add_event(ReplayAsyncEventKind event_kind,
void *opaque,
void *opaque2, uint64_t id)
{
assert(event_kind < REPLAY_ASYNC_COUNT);
if (!replay_file || replay_mode == REPLAY_MODE_NONE
|| !events_enabled) {
Event e;
e.event_kind = event_kind;
e.opaque = opaque;
e.opaque2 = opaque2;
e.id = id;
replay_run_event(&e);
return;
}
Event *event = g_malloc0(sizeof(Event));
event->event_kind = event_kind;
event->opaque = opaque;
event->opaque2 = opaque2;
event->id = id;
replay_mutex_lock();
QTAILQ_INSERT_TAIL(&events_list, event, events);
replay_mutex_unlock();
}
void replay_bh_schedule_event(QEMUBH *bh)
{
if (replay_mode != REPLAY_MODE_NONE) {
uint64_t id = replay_get_current_step();
replay_add_event(REPLAY_ASYNC_EVENT_BH, bh, NULL, id);
} else {
qemu_bh_schedule(bh);
}
}
void replay_add_input_event(struct InputEvent *event)
{
replay_add_event(REPLAY_ASYNC_EVENT_INPUT, event, NULL, 0);
}
void replay_add_input_sync_event(void)
{
replay_add_event(REPLAY_ASYNC_EVENT_INPUT_SYNC, NULL, NULL, 0);
}
static void replay_save_event(Event *event, int checkpoint)
{
if (replay_mode != REPLAY_MODE_PLAY) {
/* put the event into the file */
replay_put_event(EVENT_ASYNC);
replay_put_byte(checkpoint);
replay_put_byte(event->event_kind);
/* save event-specific data */
switch (event->event_kind) {
case REPLAY_ASYNC_EVENT_BH:
replay_put_qword(event->id);
break;
case REPLAY_ASYNC_EVENT_INPUT:
replay_save_input_event(event->opaque);
break;
case REPLAY_ASYNC_EVENT_INPUT_SYNC:
break;
case REPLAY_ASYNC_EVENT_CHAR_READ:
replay_event_char_read_save(event->opaque);
break;
default:
error_report("Unknown ID %d of replay event", read_event_kind);
exit(1);
}
}
}
/* Called with replay mutex locked */
void replay_save_events(int checkpoint)
{
while (!QTAILQ_EMPTY(&events_list)) {
Event *event = QTAILQ_FIRST(&events_list);
replay_save_event(event, checkpoint);
replay_mutex_unlock();
replay_run_event(event);
replay_mutex_lock();
QTAILQ_REMOVE(&events_list, event, events);
g_free(event);
}
}
static Event *replay_read_event(int checkpoint)
{
Event *event;
if (read_event_kind == -1) {
read_checkpoint = replay_get_byte();
read_event_kind = replay_get_byte();
read_id = -1;
replay_check_error();
}
if (checkpoint != read_checkpoint) {
return NULL;
}
/* Events that has not to be in the queue */
switch (read_event_kind) {
case REPLAY_ASYNC_EVENT_BH:
if (read_id == -1) {
read_id = replay_get_qword();
}
break;
case REPLAY_ASYNC_EVENT_INPUT:
event = g_malloc0(sizeof(Event));
event->event_kind = read_event_kind;
event->opaque = replay_read_input_event();
return event;
case REPLAY_ASYNC_EVENT_INPUT_SYNC:
event = g_malloc0(sizeof(Event));
event->event_kind = read_event_kind;
event->opaque = 0;
return event;
case REPLAY_ASYNC_EVENT_CHAR_READ:
event = g_malloc0(sizeof(Event));
event->event_kind = read_event_kind;
event->opaque = replay_event_char_read_load();
return event;
default:
error_report("Unknown ID %d of replay event", read_event_kind);
exit(1);
break;
}
QTAILQ_FOREACH(event, &events_list, events) {
if (event->event_kind == read_event_kind
&& (read_id == -1 || read_id == event->id)) {
break;
}
}
if (event) {
QTAILQ_REMOVE(&events_list, event, events);
} else {
return NULL;
}
/* Read event-specific data */
return event;
}
/* Called with replay mutex locked */
void replay_read_events(int checkpoint)
{
while (replay_data_kind == EVENT_ASYNC) {
Event *event = replay_read_event(checkpoint);
if (!event) {
break;
}
replay_mutex_unlock();
replay_run_event(event);
replay_mutex_lock();
g_free(event);
replay_finish_event();
read_event_kind = -1;
}
}
void replay_init_events(void)
{
read_event_kind = -1;
}
void replay_finish_events(void)
{
events_enabled = false;
replay_clear_events();
}
bool replay_events_enabled(void)
{
return events_enabled;
}