On (21/10/21 12:28), Sergey Senozhatsky wrote: > > > > We are using TDP. And somehow I never see (literally never) async PFs. > > It's always either hva_to_pfn_fast() or hva_to_pfn_slow() or > > __direct_map() from tdp_page_fault(). > > Hmm, and tdp_page_fault()->fast_page_fault() always fails on > !is_access_allowed(error_code, new_spte), it never handles the faults. > And I see some ->mmu_lock contention: > > spin_lock(&vcpu->kvm->mmu_lock); > __direct_map(); > spin_unlock(&vcpu->kvm->mmu_lock); > > So it might be that we setup guest memory wrongly and never get > advantages of TPD and fast page faults? No, never mind, that's probably expected and ->mmu_lock contention is not severe.
