KVM: take kvm_lock for hardware_disable() during cpu hotplug

In kvm_cpu_hotplug(), only CPU_STARTING case is protected by kvm_lock.
This patch adds missing protection for CPU_DYING case.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4023264c4cd5..f69fca7a88b5 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2140,7 +2140,9 @@ static int kvm_cpu_hotplug(struct notifier_block *notifier, unsigned long val,
         case CPU_DYING:
                 printk(KERN_INFO "kvm: disabling virtualization on CPU%d\n",
                        cpu);
+                spin_lock(&kvm_lock);
                 hardware_disable(NULL);
+                spin_unlock(&kvm_lock);
                 break;
         case CPU_STARTING:
                 printk(KERN_INFO "kvm: enabling virtualization on CPU%d\n",