This series optmizes KVM mmu notifier.change_pte() handler in x86 TDP MMU (i.e. kvm_tdp_mmu_set_spte_gfn()) by removing old dead code and prefetching notified new PFN into SPTEs directly in the handler. As in [1], .change_pte() has been dead code on x86 for 10+ years. Patch 1 drops the dead code in x86 TDP MMU to save cpu cycles and prepare for optimization in TDP MMU in patch 2. Patch 2 optimizes TDP MMU's .change_pte() handler to prefetch SPTEs in the handler directly with PFN info contained in .change_pte() to avoid that each vCPU write that triggers .change_pte() must undergo twice VMExits and TDP page faults. base-commit: fdf0eaf11452 + Sean's patch "KVM: Wrap kvm_{gfn,hva}_range.pte in a per-action union" [2] [1]: https://lore.kernel.org/lkml/ZMAO6bhan9l6ybQM@xxxxxxxxxx/ [2]: https://lore.kernel.org/lkml/20230729004144.1054885-1-seanjc@xxxxxxxxxx/ Yan Zhao (2): KVM: x86/mmu: Remove dead code in .change_pte() handler in x86 TDP MMU KVM: x86/mmu: prefetch SPTE directly in x86 TDP MMU's change_pte() handler arch/x86/kvm/mmu/tdp_mmu.c | 101 +++++++++++++++++++++++++------------ 1 file changed, 68 insertions(+), 33 deletions(-) -- 2.17.1