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| author | Sean Christopherson <seanjc@google.com> | 2022-07-12 05:07:22 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-07-14 18:31:23 +0300 |
| commit | 79e48cec6cba4eee0bd3a13f31320e33a1729931 (patch) | |
| tree | 6fbaf53d21b12bde36b5a011c3403c0a181e47b2 /arch/x86/kvm/mmu/paging_tmpl.h | |
| parent | b184b35d06b2a3de65ff2ef4303f83535572266c (diff) | |
| download | linux-79e48cec6cba4eee0bd3a13f31320e33a1729931.tar.xz | |
KVM: x86/mmu: Add optimized helper to retrieve an SPTE's index
Add spte_index() to dedup all the code that calculates a SPTE's index
into its parent's page table and/or spt array. Opportunistically tweak
the calculation to avoid pointer arithmetic, which is subtle (subtract in
8-byte chunks) and less performant (requires the compiler to generate the
subtraction).
Suggested-by: David Matlack <dmatlack@google.com>
Reviewed-by: David Matlack <dmatlack@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20220712020724.1262121-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu/paging_tmpl.h')
| -rw-r--r-- | arch/x86/kvm/mmu/paging_tmpl.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 94bfd5f723ba..f5958071220c 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -595,7 +595,7 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, if (sp->role.direct) return __direct_pte_prefetch(vcpu, sp, sptep); - i = (sptep - sp->spt) & ~(PTE_PREFETCH_NUM - 1); + i = spte_index(sptep) & ~(PTE_PREFETCH_NUM - 1); spte = sp->spt + i; for (i = 0; i < PTE_PREFETCH_NUM; i++, spte++) { @@ -933,7 +933,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva, hpa_t root_hpa) break; pte_gpa = FNAME(get_level1_sp_gpa)(sp); - pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t); + pte_gpa += spte_index(sptep) * sizeof(pt_element_t); mmu_page_zap_pte(vcpu->kvm, sp, sptep, NULL); if (is_shadow_present_pte(old_spte)) |