Messages in this thread Patch in this message | | | Date | Tue, 21 Mar 2023 15:00:18 -0700 | Subject | [PATCH v4 10/13] KVM: x86/mmu: Bypass __handle_changed_spte() when aging TDP MMU SPTEs | From | Sean Christopherson <> |
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From: Vipin Sharma <vipinsh@google.com>
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 <vipinsh@google.com> Reviewed-by: David Matlack <dmatlack@google.com> [sean: massage changelog] Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/mmu/tdp_mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index 29bb97ff266e..cdfb67ef5800 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; } -- 2.40.0.rc2.332.ga46443480c-goog
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