commit 2c579042e3be50bb40a233a6986348b4f40ed026
author Bharata B Rao <bharata@linux.vnet.ibm.com> Thu May 12 09:18:14 2016 +0530
committer David Gibson <david@gibson.dropbear.id.au> Mon May 30 14:17:05 2016 +1000
tree b68443cb824ef6abdcb0ed70cb3b94bfe4672c77
parent 4c055ab54fae39b6329c57bcb5334d59b920463e

cpu: Add a sync version of cpu_remove()

This sync API will be used by the CPU hotplug code to wait for the CPU to
completely get removed before flagging the failure to the device_add
command.

Sync version of this call is needed to correctly recover from CPU
realization failures when ->plug() handler fails.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

cpus.c

diff --git a/cpus.c b/cpus.c
index 3e3ef95..326742f 100644
--- a/cpus.c
+++ b/cpus.c
@@ -1084,6 +1084,8 @@
     } while (!cpu->unplug || cpu_can_run(cpu));
 
     qemu_kvm_destroy_vcpu(cpu);
+    cpu->created = false;
+    qemu_cond_signal(&qemu_cpu_cond);
     qemu_mutex_unlock_iothread();
     return NULL;
 }
@@ -1184,6 +1186,8 @@
         }
         if (remove_cpu) {
             qemu_tcg_destroy_vcpu(remove_cpu);
+            cpu->created = false;
+            qemu_cond_signal(&qemu_cpu_cond);
             remove_cpu = NULL;
         }
     }
@@ -1349,6 +1353,14 @@
     qemu_cpu_kick(cpu);
 }
 
+void cpu_remove_sync(CPUState *cpu)
+{
+    cpu_remove(cpu);
+    while (cpu->created) {
+        qemu_cond_wait(&qemu_cpu_cond, &qemu_global_mutex);
+    }
+}
+
 /* For temporary buffers for forming a name */
 #define VCPU_THREAD_NAME_SIZE 16