diff options
| author | Lai Jiangshan <jiangshan.ljs@antgroup.com> | 2023-02-17 07:53:21 +0800 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-03-16 17:19:55 -0700 |
| commit | 19ace7d6ca15a4395dd294286fe253a233bbf20a (patch) | |
| tree | 561f8006db35587c221c9cbf01daa1dc9d5b659d | |
| parent | 91ca7672dc7386c0d181ead2e03f4e65b73ca6b8 (diff) | |
KVM: x86/mmu: Skip calling mmu->sync_spte() when the spte is 0
Sync the spte only when the spte is set and avoid the indirect branch.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Link: https://lore.kernel.org/r/20230216235321.735214-5-jiangshanlai@gmail.com
[sean: add wrapper instead of open coding each check]
Signed-off-by: Sean Christopherson <seanjc@google.com>
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 12 | ||||
| -rw-r--r-- | arch/x86/kvm/mmu/paging_tmpl.h | 2 |
2 files changed, 11 insertions, 3 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 5bca99e50d1a..9b036a961847 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1933,6 +1933,14 @@ static bool kvm_sync_page_check(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) return true; } +static int kvm_sync_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int i) +{ + if (!sp->spt[i]) + return 0; + + return vcpu->arch.mmu->sync_spte(vcpu, sp, i); +} + static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) { int flush = 0; @@ -1942,7 +1950,7 @@ static int __kvm_sync_page(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) return -1; for (i = 0; i < SPTE_ENT_PER_PAGE; i++) { - int ret = vcpu->arch.mmu->sync_spte(vcpu, sp, i); + int ret = kvm_sync_spte(vcpu, sp, i); if (ret < -1) return -1; @@ -5766,7 +5774,7 @@ static void __kvm_mmu_invalidate_addr(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu struct kvm_mmu_page *sp = sptep_to_sp(iterator.sptep); if (sp->unsync) { - int ret = mmu->sync_spte(vcpu, sp, iterator.index); + int ret = kvm_sync_spte(vcpu, sp, iterator.index); if (ret < 0) mmu_page_zap_pte(vcpu->kvm, sp, iterator.sptep, NULL); diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h index 8ef67f76ee68..03a9577329fc 100644 --- a/arch/x86/kvm/mmu/paging_tmpl.h +++ b/arch/x86/kvm/mmu/paging_tmpl.h @@ -892,7 +892,7 @@ static int FNAME(sync_spte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, int gpa_t pte_gpa; gfn_t gfn; - if (!sp->spt[i]) + if (WARN_ON_ONCE(!sp->spt[i])) return 0; first_pte_gpa = FNAME(get_level1_sp_gpa)(sp); |