From 0671a8e75d8aeb33e15c5152147abb0d2fa0c1e6 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Fri, 4 Jun 2010 21:56:59 +0800 Subject: [PATCH] KVM: MMU: reduce remote tlb flush in kvm_mmu_pte_write() collect remote tlb flush in kvm_mmu_pte_write() path Signed-off-by: Xiao Guangrong Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 3b75689eda95..b285449e82b0 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2666,11 +2666,15 @@ static bool need_remote_flush(u64 old, u64 new) return (old & ~new & PT64_PERM_MASK) != 0; } -static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, u64 old, u64 new) +static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, bool zap_page, + bool remote_flush, bool local_flush) { - if (need_remote_flush(old, new)) + if (zap_page) + return; + + if (remote_flush) kvm_flush_remote_tlbs(vcpu->kvm); - else + else if (local_flush) kvm_mmu_flush_tlb(vcpu); } @@ -2735,6 +2739,9 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, int npte; int r; int invlpg_counter; + bool remote_flush, local_flush, zap_page; + + zap_page = remote_flush = local_flush = false; pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); @@ -2808,7 +2815,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, */ pgprintk("misaligned: gpa %llx bytes %d role %x\n", gpa, bytes, sp->role.word); - kvm_mmu_prepare_zap_page(vcpu->kvm, sp, + zap_page |= !!kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); ++vcpu->kvm->stat.mmu_flooded; continue; @@ -2833,16 +2840,19 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, if (quadrant != sp->role.quadrant) continue; } + local_flush = true; spte = &sp->spt[page_offset / sizeof(*spte)]; while (npte--) { entry = *spte; mmu_pte_write_zap_pte(vcpu, sp, spte); if (gentry) mmu_pte_write_new_pte(vcpu, sp, spte, &gentry); - mmu_pte_write_flush_tlb(vcpu, entry, *spte); + if (!remote_flush && need_remote_flush(entry, *spte)) + remote_flush = true; ++spte; } } + mmu_pte_write_flush_tlb(vcpu, zap_page, remote_flush, local_flush); kvm_mmu_commit_zap_page(vcpu->kvm, &invalid_list); kvm_mmu_audit(vcpu, "post pte write"); spin_unlock(&vcpu->kvm->mmu_lock); -- 2.20.1