diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
-rw-r--r-- | arch/x86/kvm/mmu.c | 62 |
1 files changed, 25 insertions, 37 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ca6f72ab4c3..e9534cec003 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1653,6 +1653,18 @@ static void init_shadow_page_table(struct kvm_mmu_page *sp) sp->spt[i] = 0ull; } +static void __clear_sp_write_flooding_count(struct kvm_mmu_page *sp) +{ + sp->write_flooding_count = 0; +} + +static void clear_sp_write_flooding_count(u64 *spte) +{ + struct kvm_mmu_page *sp = page_header(__pa(spte)); + + __clear_sp_write_flooding_count(sp); +} + static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, gfn_t gfn, gva_t gaddr, @@ -1696,6 +1708,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, } else if (sp->unsync) kvm_mmu_mark_parents_unsync(sp); + __clear_sp_write_flooding_count(sp); trace_kvm_mmu_get_page(sp, false); return sp; } @@ -1848,15 +1861,6 @@ static void kvm_mmu_put_page(struct kvm_mmu_page *sp, u64 *parent_pte) mmu_page_remove_parent_pte(sp, parent_pte); } -static void kvm_mmu_reset_last_pte_updated(struct kvm *kvm) -{ - int i; - struct kvm_vcpu *vcpu; - - kvm_for_each_vcpu(i, vcpu, kvm) - vcpu->arch.last_pte_updated = NULL; -} - static void kvm_mmu_unlink_parents(struct kvm *kvm, struct kvm_mmu_page *sp) { u64 *parent_pte; @@ -1916,7 +1920,6 @@ static int kvm_mmu_prepare_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp, } sp->role.invalid = 1; - kvm_mmu_reset_last_pte_updated(kvm); return ret; } @@ -2361,8 +2364,6 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, } } kvm_release_pfn_clean(pfn); - if (speculative) - vcpu->arch.last_pte_updated = sptep; } static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) @@ -3523,13 +3524,6 @@ static void mmu_pte_write_flush_tlb(struct kvm_vcpu *vcpu, bool zap_page, kvm_mmu_flush_tlb(vcpu); } -static bool last_updated_pte_accessed(struct kvm_vcpu *vcpu) -{ - u64 *spte = vcpu->arch.last_pte_updated; - - return !!(spte && (*spte & shadow_accessed_mask)); -} - static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, const u8 *new, int *bytes) { @@ -3570,22 +3564,16 @@ static u64 mmu_pte_write_fetch_gpte(struct kvm_vcpu *vcpu, gpa_t *gpa, * If we're seeing too many writes to a page, it may no longer be a page table, * or we may be forking, in which case it is better to unmap the page. */ -static bool detect_write_flooding(struct kvm_vcpu *vcpu, gfn_t gfn) +static bool detect_write_flooding(struct kvm_mmu_page *sp, u64 *spte) { - bool flooded = false; - - if (gfn == vcpu->arch.last_pt_write_gfn - && !last_updated_pte_accessed(vcpu)) { - ++vcpu->arch.last_pt_write_count; - if (vcpu->arch.last_pt_write_count >= 3) - flooded = true; - } else { - vcpu->arch.last_pt_write_gfn = gfn; - vcpu->arch.last_pt_write_count = 1; - vcpu->arch.last_pte_updated = NULL; - } + /* + * Skip write-flooding detected for the sp whose level is 1, because + * it can become unsync, then the guest page is not write-protected. + */ + if (sp->role.level == 1) + return false; - return flooded; + return ++sp->write_flooding_count >= 3; } /* @@ -3657,7 +3645,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, LIST_HEAD(invalid_list); u64 entry, gentry, *spte; int npte; - bool remote_flush, local_flush, zap_page, flooded, misaligned; + bool remote_flush, local_flush, zap_page; /* * If we don't have indirect shadow pages, it means no page is @@ -3683,12 +3671,12 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, ++vcpu->kvm->stat.mmu_pte_write; trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE); - flooded = detect_write_flooding(vcpu, gfn); mask.cr0_wp = mask.cr4_pae = mask.nxe = 1; for_each_gfn_indirect_valid_sp(vcpu->kvm, sp, gfn, node) { - misaligned = detect_write_misaligned(sp, gpa, bytes); + spte = get_written_sptes(sp, gpa, &npte); - if (misaligned || flooded) { + if (detect_write_misaligned(sp, gpa, bytes) || + detect_write_flooding(sp, spte)) { zap_page |= !!kvm_mmu_prepare_zap_page(vcpu->kvm, sp, &invalid_list); ++vcpu->kvm->stat.mmu_flooded; |