[PATCH] KVM: MMU: fix missing percpu counter destroy

[Wei Yongjun <yjwei@cn.fujitsu.com>]

commit ad05c88266b4cce1c820928ce8a0fb7690912ba1
(KVM: create aggregate kvm_total_used_mmu_pages value)
introduce percpu counter kvm_total_used_mmu_pages but never
destroy it, this may cause oops when rmmod & modprobe.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
---
 arch/x86/kvm/mmu.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index f52a965..ef485db 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -3190,6 +3190,7 @@ static void mmu_destroy_caches(void)
 void kvm_mmu_module_exit(void)
 {
 	mmu_destroy_caches();
+	percpu_counter_destroy(&kvm_total_used_mmu_pages);
 	unregister_shrinker(&mmu_shrinker);
 }
 
@@ -3212,7 +3213,9 @@ int kvm_mmu_module_init(void)
 	if (!mmu_page_header_cache)
 		goto nomem;
 
-	percpu_counter_init(&kvm_total_used_mmu_pages, 0);
+	if (percpu_counter_init(&kvm_total_used_mmu_pages, 0))
+		goto nomem;
+
 	register_shrinker(&mmu_shrinker);
 
 	return 0;
-- 
1.7.0.4