This patch introduces command line options for enabling recording or replaying
virtual machine behavior. "-record" option starts recording of the execution
and saves it into the log, specified with "fname" parameter. "-replay" option
is intended for replaying previously saved log.
Signed-off-by: Pavel Dovgalyuk <pavel.dovga...@ispras.ru>
---
cpus.c | 15 ++++++++--
qemu-options.hx | 27 +++++++++++++++++++
vl.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 116 insertions(+), 5 deletions(-)
diff --git a/cpus.c b/cpus.c
index 6adff2b..de8276b 100644
--- a/cpus.c
+++ b/cpus.c
@@ -933,12 +933,21 @@ static void qemu_wait_io_event_common(CPUState *cpu)
static void qemu_tcg_wait_io_event(void)
{
CPUState *cpu;
+ GMainContext *context = g_main_context_default();
- while (all_cpu_threads_idle()) {
- /* Start accounting real time to the virtual clock if the CPUs
- are idle. */
+ if (replay_mode == REPLAY_MODE_PLAY
+ && all_cpu_threads_idle() && first_cpu->halted) {
+ /* wakeup iothread when there is no code to execute in replay mode */
qemu_clock_warp(QEMU_CLOCK_VIRTUAL);
+ g_main_context_wakeup(context);
qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
+ } else {
+ while (all_cpu_threads_idle()) {
+ /* Start accounting real time to the virtual clock if the CPUs
+ are idle. */
+ qemu_clock_warp(QEMU_CLOCK_VIRTUAL);
+ qemu_cond_wait(tcg_halt_cond, &qemu_global_mutex);
+ }
}
while (iothread_requesting_mutex) {
diff --git a/qemu-options.hx b/qemu-options.hx
index 22cf3b9..44ad8fc 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -3380,6 +3380,33 @@ Dump json-encoded vmstate information for current
machine type to file
in @var{file}
ETEXI
+DEF("record", HAS_ARG, QEMU_OPTION_record,
+ "-record fname=<filename>[,suffix=<suffix>,snapshot=<on/off>]\n"
+ " writes replay file for latter replaying\n",
+ QEMU_ARCH_ALL)
+STEXI
+@item -record fname=@var{file}[,suffix=@var{suffix},snapshot=@var{snapshot}]
+Writes compact execution trace into @var{file}.
+Changes for disk images are written
+into separate files with @var{suffix} added. If no @var{suffix} is
+specified, "replay_qcow" is used as suffix.
+If @var{snapshot} parameter is set as off, then original disk image will be
+modified. Default value is on.
+ETEXI
+
+DEF("replay", HAS_ARG, QEMU_OPTION_replay,
+ "-replay fname=<filename>[,suffix=<suffix>,snapshot=<on/off>]\n"
+ " plays saved replay file\n", QEMU_ARCH_ALL)
+STEXI
+@item -replay
fname=@var{filename}[,suffix=@var{suffix},snapshot=@var{snapshot}]
+Plays compact execution trace from @var{filename}.
+Changes for disk images and VM states are read
+from separate files with @var{suffix} added. If no @var{suffix} is
+specified, "replay_qcow" is used as suffix.
+If @var{snapshot} parameter is set as off, then original disk image will be
+modified. Default value is on.
+ETEXI
+
HXCOMM This is the last statement. Insert new options before this line!
STEXI
@end table
diff --git a/vl.c b/vl.c
index 877a77c..fb5003e 100644
--- a/vl.c
+++ b/vl.c
@@ -548,6 +548,42 @@ static QemuOptsList qemu_icount_opts = {
},
};
+static QemuOptsList qemu_record_opts = {
+ .name = "record",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_record_opts.head),
+ .desc = {
+ {
+ .name = "fname",
+ .type = QEMU_OPT_STRING,
+ },{
+ .name = "suffix",
+ .type = QEMU_OPT_STRING,
+ },{
+ .name = "snapshot",
+ .type = QEMU_OPT_BOOL,
+ },
+ { /* end of list */ }
+ },
+};
+
+static QemuOptsList qemu_replay_opts = {
+ .name = "replay",
+ .head = QTAILQ_HEAD_INITIALIZER(qemu_replay_opts.head),
+ .desc = {
+ {
+ .name = "fname",
+ .type = QEMU_OPT_STRING,
+ },{
+ .name = "suffix",
+ .type = QEMU_OPT_STRING,
+ },{
+ .name = "snapshot",
+ .type = QEMU_OPT_BOOL,
+ },
+ { /* end of list */ }
+ },
+};
+
/**
* Get machine options
*
@@ -2711,7 +2747,9 @@ out:
int main(int argc, char **argv, char **envp)
{
int i;
- int snapshot, linux_boot;
+ int snapshot, linux_boot, replay_snapshot;
+ int not_compatible_replay_param = 0;
+ const char *icount_option = NULL;
const char *initrd_filename;
const char *kernel_filename, *kernel_cmdline;
const char *boot_order;
@@ -2784,6 +2822,8 @@ int main(int argc, char **argv, char **envp)
qemu_add_opts(&qemu_name_opts);
qemu_add_opts(&qemu_numa_opts);
qemu_add_opts(&qemu_icount_opts);
+ qemu_add_opts(&qemu_replay_opts);
+ qemu_add_opts(&qemu_record_opts);
runstate_init();
@@ -2797,6 +2837,7 @@ int main(int argc, char **argv, char **envp)
cpu_model = NULL;
ram_size = default_ram_size;
snapshot = 0;
+ replay_snapshot = 1;
cyls = heads = secs = 0;
translation = BIOS_ATA_TRANSLATION_AUTO;
@@ -2914,6 +2955,7 @@ int main(int argc, char **argv, char **envp)
break;
case QEMU_OPTION_pflash:
drive_add(IF_PFLASH, -1, optarg, PFLASH_OPTS);
+ not_compatible_replay_param++;
break;
case QEMU_OPTION_snapshot:
snapshot = 1;
@@ -3070,6 +3112,7 @@ int main(int argc, char **argv, char **envp)
#endif
case QEMU_OPTION_bt:
add_device_config(DEV_BT, optarg);
+ not_compatible_replay_param++;
break;
case QEMU_OPTION_audio_help:
AUD_help ();
@@ -3284,6 +3327,7 @@ int main(int argc, char **argv, char **envp)
if (!opts) {
exit(1);
}
+ not_compatible_replay_param++;
break;
case QEMU_OPTION_fsdev:
olist = qemu_find_opts("fsdev");
@@ -3412,6 +3456,7 @@ int main(int argc, char **argv, char **envp)
if (strncmp(optarg, "mon:", 4) == 0) {
default_monitor = 0;
}
+ not_compatible_replay_param++;
break;
case QEMU_OPTION_debugcon:
add_device_config(DEV_DEBUGCON, optarg);
@@ -3532,6 +3577,7 @@ int main(int argc, char **argv, char **envp)
if (!qemu_opts_parse(qemu_find_opts("smp-opts"), optarg, 1)) {
exit(1);
}
+ not_compatible_replay_param++;
break;
case QEMU_OPTION_vnc:
#ifdef CONFIG_VNC
@@ -3770,6 +3816,24 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
break;
+ case QEMU_OPTION_record:
+ opts = qemu_opts_parse(qemu_find_opts("record"), optarg, 0);
+ if (!opts) {
+ fprintf(stderr, "Invalid record options: %s\n", optarg);
+ exit(1);
+ }
+ replay_configure(opts, REPLAY_MODE_RECORD);
+ replay_snapshot = qemu_opt_get_bool(opts, "snapshot", 1);
+ break;
+ case QEMU_OPTION_replay:
+ opts = qemu_opts_parse(qemu_find_opts("replay"), optarg, 0);
+ if (!opts) {
+ fprintf(stderr, "Invalid replay options: %s\n", optarg);
+ exit(1);
+ }
+ replay_configure(opts, REPLAY_MODE_PLAY);
+ replay_snapshot = qemu_opt_get_bool(opts, "snapshot", 1);
+ break;
default:
os_parse_cmd_args(popt->index, optarg);
}
@@ -3784,6 +3848,12 @@ int main(int argc, char **argv, char **envp)
exit(1);
}
+ if (not_compatible_replay_param && (replay_mode != REPLAY_MODE_NONE)) {
+ fprintf(stderr, "options -smp, -pflash, -chardev, -bt, -parallel "
+ "are not compatible with record/replay\n");
+ exit(1);
+ }
+
if (qemu_opts_foreach(qemu_find_opts("sandbox"), parse_sandbox, NULL, 0)) {
exit(1);
}
@@ -4125,6 +4195,11 @@ int main(int argc, char **argv, char **envp)
qemu_opts_del(icount_opts);
}
+ if (replay_mode != REPLAY_MODE_NONE && !use_icount) {
+ fprintf(stderr, "Please enable icount to use record/replay\n");
+ exit(1);
+ }
+
/* clean up network at qemu process termination */
atexit(&net_cleanup);
@@ -4161,7 +4236,7 @@ int main(int argc, char **argv, char **envp)
}
/* open the virtual block devices */
- if (snapshot)
+ if (snapshot || (replay_mode != REPLAY_MODE_NONE && replay_snapshot))
qemu_opts_foreach(qemu_find_opts("drive"), drive_enable_snapshot,
NULL, 0);
if (qemu_opts_foreach(qemu_find_opts("drive"), drive_init_func,
&machine_class->block_default_type, 1) != 0) {
