use qemu_cpu_kick instead of cpu_exit or qemu_cpu_kick_thread

[mirror_qemu.git] / cpus.c

diff --git a/cpus.c b/cpus.c
index f38b858f9bb3aa47cb7e79a16494afeb6b9bc188..e4079103ce587ed9cf2ea191585279887d0f4d30 100644 (file)
--- a/cpus.c
+++ b/cpus.c
@@ -27,6 +27,7 @@
 
 #include "monitor/monitor.h"
 #include "qapi/qmp/qerror.h"
+#include "qemu/error-report.h"
 #include "sysemu/sysemu.h"
 #include "exec/gdbstub.h"
 #include "sysemu/dma.h"
@@ -144,7 +145,7 @@ int64_t cpu_get_icount_raw(void)
 
     icount = timers_state.qemu_icount;
     if (cpu) {
-        if (!cpu_can_do_io(cpu)) {
+        if (!cpu->can_do_io) {
             fprintf(stderr, "Bad icount read\n");
             exit(1);
         }
@@ -480,6 +481,7 @@ static const VMStateDescription icount_vmstate_timers = {
     .name = "timer/icount",
     .version_id = 1,
     .minimum_version_id = 1,
+    .needed = icount_state_needed,
     .fields = (VMStateField[]) {
         VMSTATE_INT64(qemu_icount_bias, TimersState),
         VMSTATE_INT64(qemu_icount, TimersState),
@@ -497,13 +499,9 @@ static const VMStateDescription vmstate_timers = {
         VMSTATE_INT64_V(cpu_clock_offset, TimersState, 2),
         VMSTATE_END_OF_LIST()
     },
-    .subsections = (VMStateSubsection[]) {
-        {
-            .vmsd = &icount_vmstate_timers,
-            .needed = icount_state_needed,
-        }, {
-            /* empty */
-        }
+    .subsections = (const VMStateDescription*[]) {
+        &icount_vmstate_timers,
+        NULL
     }
 };
 
@@ -665,10 +663,15 @@ static void cpu_handle_guest_debug(CPUState *cpu)
 
 static void cpu_signal(int sig)
 {
-    if (current_cpu) {
-        cpu_exit(current_cpu);
+    CPUState *cpu;
+    /* Ensure whatever caused the exit has reached the CPU threads before
+     * writing exit_request.
+     */
+    atomic_mb_set(&exit_request, 1);
+    cpu = atomic_mb_read(&tcg_current_cpu);
+    if (cpu) {
+        cpu_exit(cpu);
     }
-    exit_request = 1;
 }
 
 #ifdef CONFIG_LINUX
@@ -956,7 +959,9 @@ static void *qemu_kvm_cpu_thread_fn(void *arg)
     CPUState *cpu = arg;
     int r;
 
-    qemu_mutex_lock(&qemu_global_mutex);
+    rcu_register_thread();
+
+    qemu_mutex_lock_iothread();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
     cpu->can_do_io = 1;
@@ -997,6 +1002,8 @@ static void *qemu_dummy_cpu_thread_fn(void *arg)
     sigset_t waitset;
     int r;
 
+    rcu_register_thread();
+
     qemu_mutex_lock_iothread();
     qemu_thread_get_self(cpu->thread);
     cpu->thread_id = qemu_get_thread_id();
@@ -1036,10 +1043,12 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
 {
     CPUState *cpu = arg;
 
+    rcu_register_thread();
+
+    qemu_mutex_lock_iothread();
     qemu_tcg_init_cpu_signals();
     qemu_thread_get_self(cpu->thread);
 
-    qemu_mutex_lock(&qemu_global_mutex);
     CPU_FOREACH(cpu) {
         cpu->thread_id = qemu_get_thread_id();
         cpu->created = true;
@@ -1058,7 +1067,7 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
     }
 
     /* process any pending work */
-    exit_request = 1;
+    atomic_mb_set(&exit_request, 1);
 
     while (1) {
         tcg_exec_all();
@@ -1081,6 +1090,12 @@ static void qemu_cpu_kick_thread(CPUState *cpu)
 #ifndef _WIN32
     int err;
 
+    if (!tcg_enabled()) {
+        if (cpu->thread_kicked) {
+            return;
+        }
+        cpu->thread_kicked = true;
+    }
     err = pthread_kill(cpu->thread->thread, SIG_IPI);
     if (err) {
         fprintf(stderr, "qemu:%s: %s", __func__, strerror(err));
@@ -1118,21 +1133,14 @@ static void qemu_cpu_kick_thread(CPUState *cpu)
 void qemu_cpu_kick(CPUState *cpu)
 {
     qemu_cond_broadcast(cpu->halt_cond);
-    if (!tcg_enabled() && !cpu->thread_kicked) {
-        qemu_cpu_kick_thread(cpu);
-        cpu->thread_kicked = true;
-    }
+    qemu_cpu_kick_thread(cpu);
 }
 
 void qemu_cpu_kick_self(void)
 {
 #ifndef _WIN32
     assert(current_cpu);
-
-    if (!current_cpu->thread_kicked) {
-        qemu_cpu_kick_thread(current_cpu);
-        current_cpu->thread_kicked = true;
-    }
+    qemu_cpu_kick_thread(current_cpu);
 #else
     abort();
 #endif
@@ -1148,10 +1156,21 @@ bool qemu_in_vcpu_thread(void)
     return current_cpu && qemu_cpu_is_self(current_cpu);
 }
 
+static __thread bool iothread_locked = false;
+
+bool qemu_mutex_iothread_locked(void)
+{
+    return iothread_locked;
+}
+
 void qemu_mutex_lock_iothread(void)
 {
     atomic_inc(&iothread_requesting_mutex);
-    if (!tcg_enabled() || !first_cpu || !first_cpu->thread) {
+    /* In the simple case there is no need to bump the VCPU thread out of
+     * TCG code execution.
+     */
+    if (!tcg_enabled() || qemu_in_vcpu_thread() ||
+        !first_cpu || !first_cpu->created) {
         qemu_mutex_lock(&qemu_global_mutex);
         atomic_dec(&iothread_requesting_mutex);
     } else {
@@ -1162,10 +1181,12 @@ void qemu_mutex_lock_iothread(void)
         atomic_dec(&iothread_requesting_mutex);
         qemu_cond_broadcast(&qemu_io_proceeded_cond);
     }
+    iothread_locked = true;
 }
 
 void qemu_mutex_unlock_iothread(void)
 {
+    iothread_locked = false;
     qemu_mutex_unlock(&qemu_global_mutex);
 }
 
@@ -1346,9 +1367,8 @@ int vm_stop_force_state(RunState state)
     }
 }
 
-static int tcg_cpu_exec(CPUArchState *env)
+static int tcg_cpu_exec(CPUState *cpu)
 {
-    CPUState *cpu = ENV_GET_CPU(env);
     int ret;
 #ifdef CONFIG_PROFILER
     int64_t ti;
@@ -1383,7 +1403,7 @@ static int tcg_cpu_exec(CPUArchState *env)
         cpu->icount_decr.u16.low = decr;
         cpu->icount_extra = count;
     }
-    ret = cpu_exec(env);
+    ret = cpu_exec(cpu);
 #ifdef CONFIG_PROFILER
     tcg_time += profile_getclock() - ti;
 #endif
@@ -1410,13 +1430,12 @@ static void tcg_exec_all(void)
     }
     for (; next_cpu != NULL && !exit_request; next_cpu = CPU_NEXT(next_cpu)) {
         CPUState *cpu = next_cpu;
-        CPUArchState *env = cpu->env_ptr;
 
         qemu_clock_enable(QEMU_CLOCK_VIRTUAL,
                           (cpu->singlestep_enabled & SSTEP_NOTIMER) == 0);
 
         if (cpu_can_run(cpu)) {
-            r = tcg_cpu_exec(env);
+            r = tcg_cpu_exec(cpu);
             if (r == EXCP_DEBUG) {
                 cpu_handle_guest_debug(cpu);
                 break;
@@ -1425,7 +1444,9 @@ static void tcg_exec_all(void)
             break;
         }
     }
-    exit_request = 0;
+
+    /* 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)
@@ -1515,8 +1536,8 @@ void qmp_memsave(int64_t addr, int64_t size, const char *filename,
 
     cpu = qemu_get_cpu(cpu_index);
     if (cpu == NULL) {
-        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index",
-                  "a CPU number");
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "cpu-index",
+                   "a CPU number");
         return;
     }
 
@@ -1536,7 +1557,7 @@ void qmp_memsave(int64_t addr, int64_t size, const char *filename,
             goto exit;
         }
         if (fwrite(buf, 1, l, f) != l) {
-            error_set(errp, QERR_IO_ERROR);
+            error_setg(errp, QERR_IO_ERROR);
             goto exit;
         }
         addr += l;
@@ -1566,7 +1587,7 @@ void qmp_pmemsave(int64_t addr, int64_t size, const char *filename,
             l = size;
         cpu_physical_memory_read(addr, buf, l);
         if (fwrite(buf, 1, l, f) != l) {
-            error_set(errp, QERR_IO_ERROR);
+            error_setg(errp, QERR_IO_ERROR);
             goto exit;
         }
         addr += l;