X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=cpus-common.c;h=39f355de989f6192608d410768a9a9e464bcadd0;hb=9880e9bc63efcaf3f5230c2f93fb03068df2e465;hp=e742658e7502ad86862f548deb63b719a0755db5;hpb=2e5b09fd0e766434962327db4678ce1cda0c7241;p=mirror_qemu.git

diff --git a/cpus-common.c b/cpus-common.c
index e742658e75..39f355de98 100644
--- a/cpus-common.c
+++ b/cpus-common.c
@@ -6,7 +6,7 @@
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -22,6 +22,7 @@
 #include "exec/cpu-common.h"
 #include "hw/core/cpu.h"
 #include "sysemu/cpus.h"
+#include "qemu/lockable.h"
 
 static QemuMutex qemu_cpu_list_lock;
 static QemuCond exclusive_cond;
@@ -60,24 +61,28 @@ static bool cpu_index_auto_assigned;
 static int cpu_get_free_index(void)
 {
     CPUState *some_cpu;
-    int cpu_index = 0;
+    int max_cpu_index = 0;
 
     cpu_index_auto_assigned = true;
     CPU_FOREACH(some_cpu) {
-        cpu_index++;
+        if (some_cpu->cpu_index >= max_cpu_index) {
+            max_cpu_index = some_cpu->cpu_index + 1;
+        }
     }
-    return cpu_index;
+    return max_cpu_index;
 }
 
-static void finish_safe_work(CPUState *cpu)
+CPUTailQ cpus = QTAILQ_HEAD_INITIALIZER(cpus);
+static unsigned int cpu_list_generation_id;
+
+unsigned int cpu_list_generation_id_get(void)
 {
-    cpu_exec_start(cpu);
-    cpu_exec_end(cpu);
+    return cpu_list_generation_id;
 }
 
 void cpu_list_add(CPUState *cpu)
 {
-    qemu_mutex_lock(&qemu_cpu_list_lock);
+    QEMU_LOCK_GUARD(&qemu_cpu_list_lock);
     if (cpu->cpu_index == UNASSIGNED_CPU_INDEX) {
         cpu->cpu_index = cpu_get_free_index();
         assert(cpu->cpu_index != UNASSIGNED_CPU_INDEX);
@@ -85,29 +90,40 @@ void cpu_list_add(CPUState *cpu)
         assert(!cpu_index_auto_assigned);
     }
     QTAILQ_INSERT_TAIL_RCU(&cpus, cpu, node);
-    qemu_mutex_unlock(&qemu_cpu_list_lock);
-
-    finish_safe_work(cpu);
+    cpu_list_generation_id++;
 }
 
 void cpu_list_remove(CPUState *cpu)
 {
-    qemu_mutex_lock(&qemu_cpu_list_lock);
+    QEMU_LOCK_GUARD(&qemu_cpu_list_lock);
     if (!QTAILQ_IN_USE(cpu, node)) {
         /* there is nothing to undo since cpu_exec_init() hasn't been called */
-        qemu_mutex_unlock(&qemu_cpu_list_lock);
         return;
     }
 
-    assert(!(cpu_index_auto_assigned && cpu != QTAILQ_LAST(&cpus)));
-
     QTAILQ_REMOVE_RCU(&cpus, cpu, node);
     cpu->cpu_index = UNASSIGNED_CPU_INDEX;
-    qemu_mutex_unlock(&qemu_cpu_list_lock);
+    cpu_list_generation_id++;
+}
+
+CPUState *qemu_get_cpu(int index)
+{
+    CPUState *cpu;
+
+    CPU_FOREACH(cpu) {
+        if (cpu->cpu_index == index) {
+            return cpu;
+        }
+    }
+
+    return NULL;
 }
 
+/* current CPU in the current thread. It is only valid inside cpu_exec() */
+__thread CPUState *current_cpu;
+
 struct qemu_work_item {
-    struct qemu_work_item *next;
+    QSIMPLEQ_ENTRY(qemu_work_item) node;
     run_on_cpu_func func;
     run_on_cpu_data data;
     bool free, exclusive, done;
@@ -116,13 +132,7 @@ struct qemu_work_item {
 static void queue_work_on_cpu(CPUState *cpu, struct qemu_work_item *wi)
 {
     qemu_mutex_lock(&cpu->work_mutex);
-    if (cpu->queued_work_first == NULL) {
-        cpu->queued_work_first = wi;
-    } else {
-        cpu->queued_work_last->next = wi;
-    }
-    cpu->queued_work_last = wi;
-    wi->next = NULL;
+    QSIMPLEQ_INSERT_TAIL(&cpu->work_list, wi, node);
     wi->done = false;
     qemu_mutex_unlock(&cpu->work_mutex);
 
@@ -146,7 +156,7 @@ void do_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data,
     wi.exclusive = false;
 
     queue_work_on_cpu(cpu, &wi);
-    while (!atomic_mb_read(&wi.done)) {
+    while (!qatomic_mb_read(&wi.done)) {
         CPUState *self_cpu = current_cpu;
 
         qemu_cond_wait(&qemu_work_cond, mutex);
@@ -158,7 +168,7 @@ void async_run_on_cpu(CPUState *cpu, run_on_cpu_func func, run_on_cpu_data data)
 {
     struct qemu_work_item *wi;
 
-    wi = g_malloc0(sizeof(struct qemu_work_item));
+    wi = g_new0(struct qemu_work_item, 1);
     wi->func = func;
     wi->data = data;
     wi->free = true;
@@ -182,24 +192,29 @@ void start_exclusive(void)
     CPUState *other_cpu;
     int running_cpus;
 
+    if (current_cpu->exclusive_context_count) {
+        current_cpu->exclusive_context_count++;
+        return;
+    }
+
     qemu_mutex_lock(&qemu_cpu_list_lock);
     exclusive_idle();
 
     /* Make all other cpus stop executing.  */
-    atomic_set(&pending_cpus, 1);
+    qatomic_set(&pending_cpus, 1);
 
     /* Write pending_cpus before reading other_cpu->running.  */
     smp_mb();
     running_cpus = 0;
     CPU_FOREACH(other_cpu) {
-        if (atomic_read(&other_cpu->running)) {
+        if (qatomic_read(&other_cpu->running)) {
             other_cpu->has_waiter = true;
             running_cpus++;
             qemu_cpu_kick(other_cpu);
         }
     }
 
-    atomic_set(&pending_cpus, running_cpus + 1);
+    qatomic_set(&pending_cpus, running_cpus + 1);
     while (pending_cpus > 1) {
         qemu_cond_wait(&exclusive_cond, &qemu_cpu_list_lock);
     }
@@ -208,13 +223,20 @@ void start_exclusive(void)
      * section until end_exclusive resets pending_cpus to 0.
      */
     qemu_mutex_unlock(&qemu_cpu_list_lock);
+
+    current_cpu->exclusive_context_count = 1;
 }
 
 /* Finish an exclusive operation.  */
 void end_exclusive(void)
 {
+    current_cpu->exclusive_context_count--;
+    if (current_cpu->exclusive_context_count) {
+        return;
+    }
+
     qemu_mutex_lock(&qemu_cpu_list_lock);
-    atomic_set(&pending_cpus, 0);
+    qatomic_set(&pending_cpus, 0);
     qemu_cond_broadcast(&exclusive_resume);
     qemu_mutex_unlock(&qemu_cpu_list_lock);
 }
@@ -222,7 +244,7 @@ void end_exclusive(void)
 /* Wait for exclusive ops to finish, and begin cpu execution.  */
 void cpu_exec_start(CPUState *cpu)
 {
-    atomic_set(&cpu->running, true);
+    qatomic_set(&cpu->running, true);
 
     /* Write cpu->running before reading pending_cpus.  */
     smp_mb();
@@ -240,30 +262,29 @@ void cpu_exec_start(CPUState *cpu)
      * 3. pending_cpus == 0.  Then start_exclusive is definitely going to
      * see cpu->running == true, and it will kick the CPU.
      */
-    if (unlikely(atomic_read(&pending_cpus))) {
-        qemu_mutex_lock(&qemu_cpu_list_lock);
+    if (unlikely(qatomic_read(&pending_cpus))) {
+        QEMU_LOCK_GUARD(&qemu_cpu_list_lock);
         if (!cpu->has_waiter) {
             /* Not counted in pending_cpus, let the exclusive item
              * run.  Since we have the lock, just set cpu->running to true
              * while holding it; no need to check pending_cpus again.
              */
-            atomic_set(&cpu->running, false);
+            qatomic_set(&cpu->running, false);
             exclusive_idle();
             /* Now pending_cpus is zero.  */
-            atomic_set(&cpu->running, true);
+            qatomic_set(&cpu->running, true);
         } else {
             /* Counted in pending_cpus, go ahead and release the
              * waiter at cpu_exec_end.
              */
         }
-        qemu_mutex_unlock(&qemu_cpu_list_lock);
     }
 }
 
 /* Mark cpu as not executing, and release pending exclusive ops.  */
 void cpu_exec_end(CPUState *cpu)
 {
-    atomic_set(&cpu->running, false);
+    qatomic_set(&cpu->running, false);
 
     /* Write cpu->running before reading pending_cpus.  */
     smp_mb();
@@ -283,16 +304,15 @@ void cpu_exec_end(CPUState *cpu)
      * see cpu->running == false, and it can ignore this CPU until the
      * next cpu_exec_start.
      */
-    if (unlikely(atomic_read(&pending_cpus))) {
-        qemu_mutex_lock(&qemu_cpu_list_lock);
+    if (unlikely(qatomic_read(&pending_cpus))) {
+        QEMU_LOCK_GUARD(&qemu_cpu_list_lock);
         if (cpu->has_waiter) {
             cpu->has_waiter = false;
-            atomic_set(&pending_cpus, pending_cpus - 1);
+            qatomic_set(&pending_cpus, pending_cpus - 1);
             if (pending_cpus == 1) {
                 qemu_cond_signal(&exclusive_cond);
             }
         }
-        qemu_mutex_unlock(&qemu_cpu_list_lock);
     }
 }
 
@@ -301,7 +321,7 @@ void async_safe_run_on_cpu(CPUState *cpu, run_on_cpu_func func,
 {
     struct qemu_work_item *wi;
 
-    wi = g_malloc0(sizeof(struct qemu_work_item));
+    wi = g_new0(struct qemu_work_item, 1);
     wi->func = func;
     wi->data = data;
     wi->free = true;
@@ -314,17 +334,14 @@ void process_queued_cpu_work(CPUState *cpu)
 {
     struct qemu_work_item *wi;
 
-    if (cpu->queued_work_first == NULL) {
+    qemu_mutex_lock(&cpu->work_mutex);
+    if (QSIMPLEQ_EMPTY(&cpu->work_list)) {
+        qemu_mutex_unlock(&cpu->work_mutex);
         return;
     }
-
-    qemu_mutex_lock(&cpu->work_mutex);
-    while (cpu->queued_work_first != NULL) {
-        wi = cpu->queued_work_first;
-        cpu->queued_work_first = wi->next;
-        if (!cpu->queued_work_first) {
-            cpu->queued_work_last = NULL;
-        }
+    while (!QSIMPLEQ_EMPTY(&cpu->work_list)) {
+        wi = QSIMPLEQ_FIRST(&cpu->work_list);
+        QSIMPLEQ_REMOVE_HEAD(&cpu->work_list, node);
         qemu_mutex_unlock(&cpu->work_mutex);
         if (wi->exclusive) {
             /* Running work items outside the BQL avoids the following deadlock:
@@ -345,7 +362,7 @@ void process_queued_cpu_work(CPUState *cpu)
         if (wi->free) {
             g_free(wi);
         } else {
-            atomic_mb_set(&wi->done, true);
+            qatomic_mb_set(&wi->done, true);
         }
     }
     qemu_mutex_unlock(&cpu->work_mutex);