From: Vipin Sharma Date: Tue, 21 Mar 2023 22:00:18 +0000 (-0700) Subject: KVM: x86/mmu: Bypass __handle_changed_spte() when aging TDP MMU SPTEs X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=891f115960682b84440bdfb1ea72ab2824206db7;p=linux.git KVM: x86/mmu: Bypass __handle_changed_spte() when aging TDP MMU SPTEs Drop everything except the "tdp_mmu_spte_changed" tracepoint part of __handle_changed_spte() when aging SPTEs in the TDP MMU, as clearing the accessed status doesn't affect the SPTE's shadow-present status, whether or not the SPTE is a leaf, or change the PFN. I.e. none of the functional updates handled by __handle_changed_spte() are relevant. Losing __handle_changed_spte()'s sanity checks does mean that a bug could theoretical go unnoticed, but that scenario is extremely unlikely, e.g. would effectively require a misconfigured MMU or a locking bug elsewhere. Link: https://lore.kernel.org/all/Y9HcHRBShQgjxsQb@google.com Signed-off-by: Vipin Sharma Reviewed-by: David Matlack [sean: massage changelog] Link: https://lore.kernel.org/r/20230321220021.2119033-11-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 29bb97ff266e2..cdfb67ef58001 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -1275,8 +1275,8 @@ static bool age_gfn_range(struct kvm *kvm, struct tdp_iter *iter, iter->level); } - __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte, - new_spte, iter->level, false); + trace_kvm_tdp_mmu_spte_changed(iter->as_id, iter->gfn, iter->level, + iter->old_spte, new_spte); return true; }