cpus: move icount preparation out of tcg_exec_cpu

[mirror_qemu.git] / cpus.c

diff --git a/cpus.c b/cpus.c
index b84a392dda491f3c34ad4fe6fa56414482b2da6f..6034b104c321da88a2eee16245f99a835e06c9d6 100644 (file)
--- a/cpus.c
+++ b/cpus.c
@@ -202,14 +202,14 @@ void qemu_tcg_configure(QemuOpts *opts, Error **errp)
             } else if (use_icount) {
                 error_setg(errp, "No MTTCG when icount is enabled");
             } else {
-#ifndef TARGET_SUPPORT_MTTCG
+#ifndef TARGET_SUPPORTS_MTTCG
                 error_report("Guest not yet converted to MTTCG - "
                              "you may get unexpected results");
 #endif
                 if (!check_tcg_memory_orders_compatible()) {
                     error_report("Guest expects a stronger memory ordering "
                                  "than the host provides");
-                    error_printf("This may cause strange/hard to debug errors");
+                    error_printf("This may cause strange/hard to debug errors\n");
                 }
                 mttcg_enabled = true;
             }
@@ -229,7 +229,7 @@ int64_t cpu_get_icount_raw(void)
     CPUState *cpu = current_cpu;
 
     icount = timers_state.qemu_icount;
-    if (cpu) {
+    if (cpu && cpu->running) {
         if (!cpu->can_do_io) {
             fprintf(stderr, "Bad icount read\n");
             exit(1);
@@ -1179,47 +1179,64 @@ static void handle_icount_deadline(void)
     }
 }
 
-static int tcg_cpu_exec(CPUState *cpu)
+static void prepare_icount_for_run(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;
+
+        /* These should always be cleared by process_icount_data after
+         * each vCPU execution. However u16.high can be raised
+         * asynchronously by cpu_exit/cpu_interrupt/tcg_handle_interrupt
+         */
+        g_assert(cpu->icount_decr.u16.low == 0);
+        g_assert(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;
     }
-    qemu_mutex_unlock_iothread();
-    cpu_exec_start(cpu);
-    ret = cpu_exec(cpu);
-    cpu_exec_end(cpu);
-    qemu_mutex_lock_iothread();
-#ifdef CONFIG_PROFILER
-    tcg_time += profile_getclock() - ti;
-#endif
+}
+
+static void process_icount_data(CPUState *cpu)
+{
     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;
+
+        /* Reset the counters */
+        cpu->icount_decr.u16.low = 0;
         cpu->icount_extra = 0;
         replay_account_executed_instructions();
     }
+}
+
+
+static int tcg_cpu_exec(CPUState *cpu)
+{
+    int ret;
+#ifdef CONFIG_PROFILER
+    int64_t ti;
+#endif
+
+#ifdef CONFIG_PROFILER
+    ti = profile_getclock();
+#endif
+    qemu_mutex_unlock_iothread();
+    cpu_exec_start(cpu);
+    ret = cpu_exec(cpu);
+    cpu_exec_end(cpu);
+    qemu_mutex_lock_iothread();
+#ifdef CONFIG_PROFILER
+    tcg_time += profile_getclock() - ti;
+#endif
     return ret;
 }
 
@@ -1306,7 +1323,13 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg)
 
             if (cpu_can_run(cpu)) {
                 int r;
+
+                prepare_icount_for_run(cpu);
+
                 r = tcg_cpu_exec(cpu);
+
+                process_icount_data(cpu);
+
                 if (r == EXCP_DEBUG) {
                     cpu_handle_guest_debug(cpu);
                     break;
@@ -1344,8 +1367,9 @@ static void *qemu_hax_cpu_thread_fn(void *arg)
 {
     CPUState *cpu = arg;
     int r;
+
+    qemu_mutex_lock_iothread();
     qemu_thread_get_self(cpu->thread);
-    qemu_mutex_lock(&qemu_global_mutex);
 
     cpu->thread_id = qemu_get_thread_id();
     cpu->created = true;
@@ -1391,6 +1415,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
 {
     CPUState *cpu = arg;
 
+    g_assert(!use_icount);
+
     rcu_register_thread();
 
     qemu_mutex_lock_iothread();
@@ -1433,8 +1459,6 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
             }
         }
 
-        handle_icount_deadline();
-
         atomic_mb_set(&cpu->exit_request, 0);
         qemu_tcg_wait_io_event(cpu);
     }