On 6/14/2018 6:33 PM, Vitaly Kuznetsov wrote: > Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx> writes: > >> On 6/12/2018 11:12 PM, Vitaly Kuznetsov wrote: >>> Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx> writes: >>> >>>> >>>> +static int vmx_remote_flush_tlb(struct kvm *kvm) >>>> +{ >>>> + struct kvm_vcpu *vcpu = kvm_get_vcpu(kvm, 0); >>>> + >>>> + if (!VALID_PAGE(vcpu->arch.mmu.root_hpa)) >>>> + return -1; >>> >>> Why vcpu0? Can arch.mmu.root_hpa-s differ across vCPUs? What happens if >>> they do? >> >> Yes, it may take place that arch.mmu.root_hpa is differ across vCPUs. >> We may check all vcpu root_hpa and use the hypercall when there is only >> one validated ept table. If not, go back to current way. >> > > I'd suggest an optimization: keep track of wether root_hpas are equal > across all vcpus (check this on change). > Good suggestion. I will try it. Thanks.