[Qemu-devel] [PATCH v3 01/10] exec: Remove cpu from cpus list during cpu_exec_exit()

[Matthew Rosato <mjrosato@linux.vnet.ibm.com>]

From: Bharata B Rao <bharata@linux.vnet.ibm.com>

CPUState *cpu gets added to the cpus list during cpu_exec_init(). It
should be removed from cpu_exec_exit().

cpu_exec_init() is called from generic CPU::instance_finalize and some
archs like PowerPC call it from CPU unrealizefn. So ensure that we
dequeue the cpu only once.

Now -1 value for cpu->cpu_index indicates that we have already dequeued
the cpu for CONFIG_USER_ONLY case also.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 exec.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/exec.c b/exec.c
index 7115403..c8da9d4 100644
--- a/exec.c
+++ b/exec.c
@@ -596,6 +596,7 @@ void cpu_exec_exit(CPUState *cpu)
         return;
     }
 
+    QTAILQ_REMOVE(&cpus, cpu, node);
     bitmap_clear(cpu_index_map, cpu->cpu_index, 1);
     cpu->cpu_index = -1;
 }
@@ -614,6 +615,15 @@ static int cpu_get_free_index(Error **errp)
 
 void cpu_exec_exit(CPUState *cpu)
 {
+    cpu_list_lock();
+    if (cpu->cpu_index == -1) {
+        cpu_list_unlock();
+        return;
+    }
+
+    QTAILQ_REMOVE(&cpus, cpu, node);
+    cpu->cpu_index = -1;
+    cpu_list_unlock();
 }
 #endif
 
-- 
1.9.1