>+static int tdp_mmu_install_spte(struct kvm_vcpu *vcpu,
>+ struct tdp_iter *iter,
>+ u64 spte)
>+{
>+ kvm_pfn_t pfn = 0;
>+ int ret = 0;
>+
>+ if (is_mirror_sptep(iter->sptep) && !is_frozen_spte(spte)) {
>+ pfn = spte_to_pfn(spte);
>+ ret = static_call(kvm_x86_phys_prepare)(vcpu, pfn);
nit: kvm is using kvm_x86_call() in most of cases, e.g.,
ret = kvm_x86_call(phys_prepare)(vcpu, pfn);
>+ }
>+ if (ret)
>+ return ret;
fold this chunk into the if() statement above to align with tdp_mmu_link_sp()
below?
I'm concerned about handling phys_prepare() failures. Such failures may not be
recoverable. ...
>+ ret = tdp_mmu_set_spte_atomic(vcpu->kvm, iter, spte);
>+ if (pfn && ret)
>+ static_call(kvm_x86_phys_cleanup)(pfn);
>+
>+ return ret;
>+}
>+
> /*
> * Installs a last-level SPTE to handle a TDP page fault.
> * (NPT/EPT violation/misconfiguration)
>@@ -1170,7 +1190,7 @@ static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu,
>
> if (new_spte == iter->old_spte)
> ret = RET_PF_SPURIOUS;
>- else if (tdp_mmu_set_spte_atomic(vcpu->kvm, iter, new_spte))
>+ else if (tdp_mmu_install_spte(vcpu, iter, new_spte))
> return RET_PF_RETRY;
if RET_FP_RETRY is returned here, it could potentially cause an infinite loop.
I think we need a KVM_BUG_ON() somewhere.
