In preparation for multi-threaded TCG we remove tcg_exec_all and move
all the CPU cycling into the main thread function. When MTTCG is enabled
we shall use a separate thread function which only handles one vCPU.
Signed-off-by: Alex Bennée <alex.ben...@linaro.org>
---
v2
- update timer calls to new API on rebase
v3
- move tcg_cpu_exec above thread function, drop static fwd declaration
---
cpus.c | 185 +++++++++++++++++++++++++++++++----------------------------------
1 file changed, 89 insertions(+), 96 deletions(-)
diff --git a/cpus.c b/cpus.c
index c404dd7..4cc2ce6 100644
--- a/cpus.c
+++ b/cpus.c
@@ -69,7 +69,6 @@
#endif /* CONFIG_LINUX */
-static CPUState *next_cpu;
int64_t max_delay;
int64_t max_advance;
@@ -1119,7 +1118,67 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
#endif
}
-static void tcg_exec_all(void);
+static int64_t tcg_get_icount_limit(void)
+{
+ int64_t deadline;
+
+ if (replay_mode != REPLAY_MODE_PLAY) {
+ deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
+
+ /* Maintain prior (possibly buggy) behaviour where if no deadline
+ * was set (as there is no QEMU_CLOCK_VIRTUAL timer) or it is more than
+ * INT32_MAX nanoseconds ahead, we still use INT32_MAX
+ * nanoseconds.
+ */
+ if ((deadline < 0) || (deadline > INT32_MAX)) {
+ deadline = INT32_MAX;
+ }
+
+ return qemu_icount_round(deadline);
+ } else {
+ return replay_get_instructions();
+ }
+}
+
+static int tcg_cpu_exec(CPUState *cpu)
+{
+ int ret;
+#ifdef CONFIG_PROFILER
+ int64_t ti;
+#endif
+
+#ifdef CONFIG_PROFILER
+ ti = profile_getclock();
+#endif
+ if (use_icount) {
+ int64_t count;
+ int decr;
+ timers_state.qemu_icount -= (cpu->icount_decr.u16.low
+ + cpu->icount_extra);
+ cpu->icount_decr.u16.low = 0;
+ cpu->icount_extra = 0;
+ count = tcg_get_icount_limit();
+ timers_state.qemu_icount += count;
+ decr = (count > 0xffff) ? 0xffff : count;
+ count -= decr;
+ cpu->icount_decr.u16.low = decr;
+ cpu->icount_extra = count;
+ }
+ ret = cpu_exec(cpu);
+#ifdef CONFIG_PROFILER
+ tcg_time += profile_getclock() - ti;
+#endif
+ if (use_icount) {
+ /* Fold pending instructions back into the
+ instruction counter, and clear the interrupt flag. */
+ timers_state.qemu_icount -= (cpu->icount_decr.u16.low
+ + cpu->icount_extra);
+ cpu->icount_decr.u32 = 0;
+ cpu->icount_extra = 0;
+ replay_account_executed_instructions();
+ }
+ return ret;
+}
static void *qemu_tcg_cpu_thread_fn(void *arg)
{
@@ -1150,8 +1209,35 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
/* process any pending work */
atomic_mb_set(&exit_request, 1);
+ cpu = first_cpu;
+
while (1) {
- tcg_exec_all();
+ /* Account partial waits to QEMU_CLOCK_VIRTUAL. */
+ qemu_account_warp_timer();
+
+ if (!cpu) {
+ cpu = first_cpu;
+ }
+
+ for (; cpu != NULL && !exit_request; cpu = CPU_NEXT(cpu)) {
+
+ qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
+ (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
+
+ if (cpu_can_run(cpu)) {
+ int r = tcg_cpu_exec(cpu);
+ if (r == EXCP_DEBUG) {
+ cpu_handle_guest_debug(cpu);
+ break;
+ }
+ } else if (cpu->stop || cpu->stopped) {
+ break;
+ }
+
+ } /* for cpu.. */
+
+ /* Pairs with smp_wmb in qemu_cpu_kick. */
+ atomic_mb_set(&exit_request, 0);
if (use_icount) {
int64_t deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
@@ -1448,99 +1534,6 @@ int vm_stop_force_state(RunState state)
}
}
-static int64_t tcg_get_icount_limit(void)
-{
- int64_t deadline;
-
- if (replay_mode != REPLAY_MODE_PLAY) {
- deadline = qemu_clock_deadline_ns_all(QEMU_CLOCK_VIRTUAL);
-
- /* Maintain prior (possibly buggy) behaviour where if no deadline
- * was set (as there is no QEMU_CLOCK_VIRTUAL timer) or it is more than
- * INT32_MAX nanoseconds ahead, we still use INT32_MAX
- * nanoseconds.
- */
- if ((deadline < 0) || (deadline > INT32_MAX)) {
- deadline = INT32_MAX;
- }
-
- return qemu_icount_round(deadline);
- } else {
- return replay_get_instructions();
- }
-}
-
-static int tcg_cpu_exec(CPUState *cpu)
-{
- int ret;
-#ifdef CONFIG_PROFILER
- int64_t ti;
-#endif
-
-#ifdef CONFIG_PROFILER
- ti = profile_getclock();
-#endif
- if (use_icount) {
- int64_t count;
- int decr;
- timers_state.qemu_icount -= (cpu->icount_decr.u16.low
- + cpu->icount_extra);
- cpu->icount_decr.u16.low = 0;
- cpu->icount_extra = 0;
- count = tcg_get_icount_limit();
- timers_state.qemu_icount += count;
- decr = (count > 0xffff) ? 0xffff : count;
- count -= decr;
- cpu->icount_decr.u16.low = decr;
- cpu->icount_extra = count;
- }
- ret = cpu_exec(cpu);
-#ifdef CONFIG_PROFILER
- tcg_time += profile_getclock() - ti;
-#endif
- if (use_icount) {
- /* Fold pending instructions back into the
- instruction counter, and clear the interrupt flag. */
- timers_state.qemu_icount -= (cpu->icount_decr.u16.low
- + cpu->icount_extra);
- cpu->icount_decr.u32 = 0;
- cpu->icount_extra = 0;
- replay_account_executed_instructions();
- }
- return ret;
-}
-
-static void tcg_exec_all(void)
-{
- int r;
-
- /* Account partial waits to QEMU_CLOCK_VIRTUAL. */
- qemu_account_warp_timer();
-
- if (next_cpu == NULL) {
- next_cpu = first_cpu;
- }
- for (; next_cpu != NULL && !exit_request; next_cpu = CPU_NEXT(next_cpu)) {
- CPUState *cpu = next_cpu;
-
- qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
- (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
-
- if (cpu_can_run(cpu)) {
- r = tcg_cpu_exec(cpu);
- if (r == EXCP_DEBUG) {
- cpu_handle_guest_debug(cpu);
- break;
- }
- } else if (cpu->stop || cpu->stopped) {
- break;
- }
- }
-
- /* Pairs with smp_wmb in qemu_cpu_kick. */
- atomic_mb_set(&exit_request, 0);
-}
-
void list_cpus(FILE *f, fprintf_function cpu_fprintf, const char *optarg)
{
/* XXX: implement xxx_cpu_list for targets that still miss it */
--
2.7.4
