On 27/09/2018 05:48, Tianyu Lan wrote: > + > + if (range && kvm_x86_ops->tlb_remote_flush_with_range) { > + /* > + * Read tlbs_dirty before flushing tlbs in order > + * to track dirty tlbs during flushing. > + */ > + long dirty_count = smp_load_acquire(&kvm->tlbs_dirty); > + > + ret = kvm_x86_ops->tlb_remote_flush_with_range(kvm, range); > + cmpxchg(&kvm->tlbs_dirty, dirty_count, 0); This is wrong, because it's not the entire TLB that is flushed. So you cannot do the cmpxchg here. Paolo > + > + if (ret) > + kvm_flush_remote_tlbs(kvm); > +} > +