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[Qemu-devel] [RFC PATCH v2 10/26] icount: fixed saving/restoring of icou
From: |
Pavel Dovgalyuk |
Subject: |
[Qemu-devel] [RFC PATCH v2 10/26] icount: fixed saving/restoring of icount warp timers |
Date: |
Tue, 14 Nov 2017 11:17:28 +0300 |
User-agent: |
StGit/0.17.1-dirty |
This patch adds saving and restoring of the icount warp
timers in the vmstate.
It is needed because there timers affect the virtual clock value.
Therefore determinism of the execution in icount record/replay mode
depends on determinism of the timers.
Signed-off-by: Pavel Dovgalyuk <address@hidden>
---
cpus.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 66 insertions(+), 19 deletions(-)
diff --git a/cpus.c b/cpus.c
index c728f3a..7a3abea 100644
--- a/cpus.c
+++ b/cpus.c
@@ -119,16 +119,11 @@ static bool all_cpu_threads_idle(void)
/* Protected by TimersState seqlock */
static bool icount_sleep = true;
-static int64_t vm_clock_warp_start = -1;
/* Conversion factor from emulated instructions to virtual clock ticks. */
static int icount_time_shift;
/* Arbitrarily pick 1MIPS as the minimum allowable speed. */
#define MAX_ICOUNT_SHIFT 10
-static QEMUTimer *icount_rt_timer;
-static QEMUTimer *icount_vm_timer;
-static QEMUTimer *icount_warp_timer;
-
typedef struct TimersState {
/* Protected by BQL. */
int64_t cpu_ticks_prev;
@@ -146,6 +141,11 @@ typedef struct TimersState {
int64_t qemu_icount_bias;
/* Only written by TCG thread */
int64_t qemu_icount;
+ /* for adjusting icount */
+ int64_t vm_clock_warp_start;
+ QEMUTimer *icount_rt_timer;
+ QEMUTimer *icount_vm_timer;
+ QEMUTimer *icount_warp_timer;
} TimersState;
static TimersState timers_state;
@@ -431,14 +431,14 @@ static void icount_adjust(void)
static void icount_adjust_rt(void *opaque)
{
- timer_mod(icount_rt_timer,
+ timer_mod(timers_state.icount_rt_timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL_RT) + 1000);
icount_adjust();
}
static void icount_adjust_vm(void *opaque)
{
- timer_mod(icount_vm_timer,
+ timer_mod(timers_state.icount_vm_timer,
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
NANOSECONDS_PER_SECOND / 10);
icount_adjust();
@@ -459,7 +459,7 @@ static void icount_warp_rt(void)
*/
do {
seq = seqlock_read_begin(&timers_state.vm_clock_seqlock);
- warp_start = vm_clock_warp_start;
+ warp_start = timers_state.vm_clock_warp_start;
} while (seqlock_read_retry(&timers_state.vm_clock_seqlock, seq));
if (warp_start == -1) {
@@ -472,7 +472,7 @@ static void icount_warp_rt(void)
cpu_get_clock_locked());
int64_t warp_delta;
- warp_delta = clock - vm_clock_warp_start;
+ warp_delta = clock - timers_state.vm_clock_warp_start;
if (use_icount == 2) {
/*
* In adaptive mode, do not let QEMU_CLOCK_VIRTUAL run too
@@ -484,7 +484,7 @@ static void icount_warp_rt(void)
}
timers_state.qemu_icount_bias += warp_delta;
}
- vm_clock_warp_start = -1;
+ timers_state.vm_clock_warp_start = -1;
seqlock_write_end(&timers_state.vm_clock_seqlock);
if (qemu_clock_expired(QEMU_CLOCK_VIRTUAL)) {
@@ -593,11 +593,13 @@ void qemu_start_warp_timer(void)
* every 100ms.
*/
seqlock_write_begin(&timers_state.vm_clock_seqlock);
- if (vm_clock_warp_start == -1 || vm_clock_warp_start > clock) {
- vm_clock_warp_start = clock;
+ if (timers_state.vm_clock_warp_start == -1
+ || timers_state.vm_clock_warp_start > clock) {
+ timers_state.vm_clock_warp_start = clock;
}
seqlock_write_end(&timers_state.vm_clock_seqlock);
- timer_mod_anticipate(icount_warp_timer, clock + deadline);
+ timer_mod_anticipate(timers_state.icount_warp_timer,
+ clock + deadline);
}
} else if (deadline == 0) {
qemu_clock_notify(QEMU_CLOCK_VIRTUAL);
@@ -622,7 +624,7 @@ static void qemu_account_warp_timer(void)
return;
}
- timer_del(icount_warp_timer);
+ timer_del(timers_state.icount_warp_timer);
icount_warp_rt();
}
@@ -631,6 +633,45 @@ static bool icount_state_needed(void *opaque)
return use_icount;
}
+static bool warp_timer_state_needed(void *opaque)
+{
+ TimersState *s = opaque;
+ return s->icount_warp_timer != NULL;
+}
+
+static bool adjust_timers_state_needed(void *opaque)
+{
+ TimersState *s = opaque;
+ return s->icount_rt_timer != NULL;
+}
+
+/*
+ * Subsection for warp timer migration is optional, because may not be created
+ */
+static const VMStateDescription icount_vmstate_warp_timer = {
+ .name = "timer/icount/warp_timer",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = warp_timer_state_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_INT64(vm_clock_warp_start, TimersState),
+ VMSTATE_TIMER_PTR(icount_warp_timer, TimersState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static const VMStateDescription icount_vmstate_adjust_timers = {
+ .name = "timer/icount/timers",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .needed = adjust_timers_state_needed,
+ .fields = (VMStateField[]) {
+ VMSTATE_TIMER_PTR(icount_rt_timer, TimersState),
+ VMSTATE_TIMER_PTR(icount_vm_timer, TimersState),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
/*
* This is a subsection for icount migration.
*/
@@ -643,6 +684,11 @@ static const VMStateDescription icount_vmstate_timers = {
VMSTATE_INT64(qemu_icount_bias, TimersState),
VMSTATE_INT64(qemu_icount, TimersState),
VMSTATE_END_OF_LIST()
+ },
+ .subsections = (const VMStateDescription*[]) {
+ &icount_vmstate_warp_timer,
+ &icount_vmstate_adjust_timers,
+ NULL
}
};
@@ -753,7 +799,7 @@ void configure_icount(QemuOpts *opts, Error **errp)
icount_sleep = qemu_opt_get_bool(opts, "sleep", true);
if (icount_sleep) {
- icount_warp_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT,
+ timers_state.icount_warp_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT,
icount_timer_cb, NULL);
}
@@ -787,13 +833,14 @@ void configure_icount(QemuOpts *opts, Error **errp)
the virtual time trigger catches emulated time passing too fast.
Realtime triggers occur even when idle, so use them less frequently
than VM triggers. */
- icount_rt_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL_RT,
+ timers_state.vm_clock_warp_start = -1;
+ timers_state.icount_rt_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL_RT,
icount_adjust_rt, NULL);
- timer_mod(icount_rt_timer,
+ timer_mod(timers_state.icount_rt_timer,
qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL_RT) + 1000);
- icount_vm_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
+ timers_state.icount_vm_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL,
icount_adjust_vm, NULL);
- timer_mod(icount_vm_timer,
+ timer_mod(timers_state.icount_vm_timer,
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) +
NANOSECONDS_PER_SECOND / 10);
}
- [Qemu-devel] [RFC PATCH v2 04/26] replay: fix processing async events, (continued)
- [Qemu-devel] [RFC PATCH v2 04/26] replay: fix processing async events, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 05/26] replay: fixed replay_enable_events, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 06/26] replay: fix save/load vm for non-empty queue, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 07/26] replay: added replay log format description, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 08/26] replay: make safe vmstop at record/replay, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 09/26] replay: save prior value of the host clock, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 10/26] icount: fixed saving/restoring of icount warp timers,
Pavel Dovgalyuk <=
- [Qemu-devel] [RFC PATCH v2 11/26] target/arm/arm-powertctl: drop BQL assertions, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 12/26] cpus: push BQL lock to qemu_*_wait_io_event, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 13/26] cpus: only take BQL for sleeping threads, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 14/26] replay/replay.c: bump REPLAY_VERSION again, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 15/26] replay/replay-internal.c: track holding of replay_lock, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 16/26] replay: make locking visible outside replay code, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 17/26] replay: push replay_mutex_lock up the call tree, Pavel Dovgalyuk, 2017/11/14
- [Qemu-devel] [RFC PATCH v2 18/26] cpu-exec: don't overwrite exception_index, Pavel Dovgalyuk, 2017/11/14