[Qemu-devel] [PATCH v6 03/11] exec: Do vmstate unregistration from cpu_exec_exit()

[Bharata B Rao <bharata@linux.vnet.ibm.com>]

cpu_exec_init() does vmstate_register and register_savevm for the CPU device.
These need to be undone from cpu_exec_exit(). These changes are needed to
support CPU hot removal and also to correctly fail hotplug attempts
beyond max_cpus.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 exec.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/exec.c b/exec.c
index 25c0f36..d56cf71 100644
--- a/exec.c
+++ b/exec.c
@@ -573,6 +573,8 @@ static int cpu_get_free_index(Error **errp)
 
 void cpu_exec_exit(CPUState *cpu)
 {
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
     if (cpu->cpu_index == -1) {
         /* cpu_index was never allocated by this @cpu or was already freed. */
         return;
@@ -581,6 +583,15 @@ void cpu_exec_exit(CPUState *cpu)
     QTAILQ_REMOVE(&cpus, cpu, node);
     bitmap_clear(cpu_index_map, cpu->cpu_index, 1);
     cpu->cpu_index = -1;
+    if (cc->vmsd != NULL) {
+        vmstate_unregister(NULL, cc->vmsd, cpu);
+    }
+#if defined(CPU_SAVE_VERSION)
+    unregister_savevm(NULL, "cpu", cpu->env_ptr);
+#endif
+    if (qdev_get_vmsd(DEVICE(cpu)) == NULL) {
+        vmstate_unregister(NULL, &vmstate_cpu_common, cpu);
+    }
 }
 #else
 
@@ -597,6 +608,8 @@ static int cpu_get_free_index(Error **errp)
 
 void cpu_exec_exit(CPUState *cpu)
 {
+    CPUClass *cc = CPU_GET_CLASS(cpu);
+
     cpu_list_lock();
     if (cpu->cpu_index == -1) {
         cpu_list_unlock();
@@ -606,6 +619,13 @@ void cpu_exec_exit(CPUState *cpu)
     QTAILQ_REMOVE(&cpus, cpu, node);
     cpu->cpu_index = -1;
     cpu_list_unlock();
+
+    if (cc->vmsd != NULL) {
+        vmstate_unregister(NULL, cc->vmsd, cpu);
+    }
+    if (qdev_get_vmsd(DEVICE(cpu)) == NULL) {
+        vmstate_unregister(NULL, &vmstate_cpu_common, cpu);
+    }
 }
 #endif
 
-- 
2.1.0