KVM: Simplify kvm->tlbs_dirty handling

When this was introduced, kvm_flush_remote_tlbs() could be called
without holding mmu_lock.  It is now acknowledged that the function
must be called before releasing mmu_lock, and all callers have already
been changed to do so.

There is no need to use smp_mb() and cmpxchg() any more.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a9e999a..f5668a4 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -186,12 +186,9 @@ static bool make_all_cpus_request(struct kvm *kvm, unsigned int req)
 
 void kvm_flush_remote_tlbs(struct kvm *kvm)
 {
-	long dirty_count = kvm->tlbs_dirty;
-
-	smp_mb();
 	if (make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
 		++kvm->stat.remote_tlb_flush;
-	cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
+	kvm->tlbs_dirty = false;
 }
 EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);