On 14/03/2016 10:41, Suravee Suthikulpanit wrote: >>>>>> >>>>>> + kvm_lapic_set_vector(vec, avic_get_bk_page_entry(svm, >>>>>> APIC_IRR)); >>>> >>>> (I think that smp_mb here would make sense, even though we're fine now >>>> thanks to re-checking vcpu->mode in kvm_vcpu_kick. >>> >>> Right, though only a smp_mb__after_atomic() is required (which is a >>> compiler barrier). It is similarly required in vmx. >> >> True, kvm_lapic_set_vector uses a lock prefix. >> >> (I thought it behaves like atomic_set, which would require MFENCE for >> correct ordering here ... I don't like smp_mb__after_atomic much >> because of the discrepancy on some atomic operations.) >> > > So, should i just use smb_mb() in this case?
You should use smp_mb__after_atomic(). Paolo
