diff options
Diffstat (limited to 'arch/x86/kvm/mmu.c')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 169 |
1 files changed, 151 insertions, 18 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7e7c3969f7a..0bfe2bd305e 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -66,7 +66,8 @@ static void kvm_mmu_audit(struct kvm_vcpu *vcpu, const char *msg) {} #endif #if defined(MMU_DEBUG) || defined(AUDIT) -static int dbg = 1; +static int dbg = 0; +module_param(dbg, bool, 0644); #endif #ifndef MMU_DEBUG @@ -652,6 +653,84 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn) account_shadowed(kvm, gfn); } +static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp) +{ + u64 *spte; + int need_tlb_flush = 0; + + while ((spte = rmap_next(kvm, rmapp, NULL))) { + BUG_ON(!(*spte & PT_PRESENT_MASK)); + rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte); + rmap_remove(kvm, spte); + set_shadow_pte(spte, shadow_trap_nonpresent_pte); + need_tlb_flush = 1; + } + return need_tlb_flush; +} + +static int kvm_handle_hva(struct kvm *kvm, unsigned long hva, + int (*handler)(struct kvm *kvm, unsigned long *rmapp)) +{ + int i; + int retval = 0; + + /* + * If mmap_sem isn't taken, we can look the memslots with only + * the mmu_lock by skipping over the slots with userspace_addr == 0. + */ + for (i = 0; i < kvm->nmemslots; i++) { + struct kvm_memory_slot *memslot = &kvm->memslots[i]; + unsigned long start = memslot->userspace_addr; + unsigned long end; + + /* mmu_lock protects userspace_addr */ + if (!start) + continue; + + end = start + (memslot->npages << PAGE_SHIFT); + if (hva >= start && hva < end) { + gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT; + retval |= handler(kvm, &memslot->rmap[gfn_offset]); + retval |= handler(kvm, + &memslot->lpage_info[ + gfn_offset / + KVM_PAGES_PER_HPAGE].rmap_pde); + } + } + + return retval; +} + +int kvm_unmap_hva(struct kvm *kvm, unsigned long hva) +{ + return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp); +} + +static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp) +{ + u64 *spte; + int young = 0; + + spte = rmap_next(kvm, rmapp, NULL); + while (spte) { + int _young; + u64 _spte = *spte; + BUG_ON(!(_spte & PT_PRESENT_MASK)); + _young = _spte & PT_ACCESSED_MASK; + if (_young) { + young = 1; + clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte); + } + spte = rmap_next(kvm, rmapp, spte); + } + return young; +} + +int kvm_age_hva(struct kvm *kvm, unsigned long hva) +{ + return kvm_handle_hva(kvm, hva, kvm_age_rmapp); +} + #ifdef MMU_DEBUG static int is_empty_shadow_page(u64 *spt) { @@ -776,6 +855,15 @@ static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, BUG(); } +static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu, + struct kvm_mmu_page *sp) +{ + int i; + + for (i = 0; i < PT64_ENT_PER_PAGE; ++i) + sp->spt[i] = shadow_trap_nonpresent_pte; +} + static struct kvm_mmu_page *kvm_mmu_lookup_page(struct kvm *kvm, gfn_t gfn) { unsigned index; @@ -841,7 +929,10 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu, hlist_add_head(&sp->hash_link, bucket); if (!metaphysical) rmap_write_protect(vcpu->kvm, gfn); - vcpu->arch.mmu.prefetch_page(vcpu, sp); + if (shadow_trap_nonpresent_pte != shadow_notrap_nonpresent_pte) + vcpu->arch.mmu.prefetch_page(vcpu, sp); + else + nonpaging_prefetch_page(vcpu, sp); return sp; } @@ -917,14 +1008,17 @@ static void kvm_mmu_zap_page(struct kvm *kvm, struct kvm_mmu_page *sp) } kvm_mmu_page_unlink_children(kvm, sp); if (!sp->root_count) { - if (!sp->role.metaphysical) + if (!sp->role.metaphysical && !sp->role.invalid) unaccount_shadowed(kvm, sp->gfn); hlist_del(&sp->hash_link); kvm_mmu_free_page(kvm, sp); } else { + int invalid = sp->role.invalid; list_move(&sp->link, &kvm->arch.active_mmu_pages); sp->role.invalid = 1; kvm_reload_remote_mmus(kvm); + if (!sp->role.metaphysical && !invalid) + unaccount_shadowed(kvm, sp->gfn); } kvm_mmu_reset_last_pte_updated(kvm); } @@ -1103,7 +1197,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, mark_page_dirty(vcpu->kvm, gfn); pgprintk("%s: setting spte %llx\n", __func__, spte); - pgprintk("instantiating %s PTE (%s) at %d (%llx) addr %llx\n", + pgprintk("instantiating %s PTE (%s) at %ld (%llx) addr %p\n", (spte&PT_PAGE_SIZE_MASK)? "2MB" : "4kB", (spte&PT_WRITABLE_MASK)?"RW":"R", gfn, spte, shadow_pte); set_shadow_pte(shadow_pte, spte); @@ -1122,8 +1216,10 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, else kvm_release_pfn_clean(pfn); } - if (!ptwrite || !*ptwrite) + if (speculative) { vcpu->arch.last_pte_updated = shadow_pte; + vcpu->arch.last_pte_gfn = gfn; + } } static void nonpaging_new_cr3(struct kvm_vcpu *vcpu) @@ -1171,9 +1267,10 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write, return -ENOMEM; } - table[index] = __pa(new_table->spt) - | PT_PRESENT_MASK | PT_WRITABLE_MASK - | shadow_user_mask | shadow_x_mask; + set_shadow_pte(&table[index], + __pa(new_table->spt) + | PT_PRESENT_MASK | PT_WRITABLE_MASK + | shadow_user_mask | shadow_x_mask); } table_addr = table[index] & PT64_BASE_ADDR_MASK; } @@ -1184,6 +1281,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) int r; int largepage = 0; pfn_t pfn; + unsigned long mmu_seq; down_read(¤t->mm->mmap_sem); if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) { @@ -1191,6 +1289,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) largepage = 1; } + mmu_seq = vcpu->kvm->mmu_notifier_seq; + /* implicit mb(), we'll read before PT lock is unlocked */ pfn = gfn_to_pfn(vcpu->kvm, gfn); up_read(¤t->mm->mmap_sem); @@ -1201,6 +1301,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) } spin_lock(&vcpu->kvm->mmu_lock); + if (mmu_notifier_retry(vcpu, mmu_seq)) + goto out_unlock; kvm_mmu_free_some_pages(vcpu); r = __direct_map(vcpu, v, write, largepage, gfn, pfn, PT32E_ROOT_LEVEL); @@ -1208,18 +1310,14 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn) return r; -} - - -static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu, - struct kvm_mmu_page *sp) -{ - int i; - for (i = 0; i < PT64_ENT_PER_PAGE; ++i) - sp->spt[i] = shadow_trap_nonpresent_pte; +out_unlock: + spin_unlock(&vcpu->kvm->mmu_lock); + kvm_release_pfn_clean(pfn); + return 0; } + static void mmu_free_roots(struct kvm_vcpu *vcpu) { int i; @@ -1335,6 +1433,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, int r; int largepage = 0; gfn_t gfn = gpa >> PAGE_SHIFT; + unsigned long mmu_seq; ASSERT(vcpu); ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa)); @@ -1348,6 +1447,8 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, gfn &= ~(KVM_PAGES_PER_HPAGE-1); largepage = 1; } + mmu_seq = vcpu->kvm->mmu_notifier_seq; + /* implicit mb(), we'll read before PT lock is unlocked */ pfn = gfn_to_pfn(vcpu->kvm, gfn); up_read(¤t->mm->mmap_sem); if (is_error_pfn(pfn)) { @@ -1355,12 +1456,19 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa, return 1; } spin_lock(&vcpu->kvm->mmu_lock); + if (mmu_notifier_retry(vcpu, mmu_seq)) + goto out_unlock; kvm_mmu_free_some_pages(vcpu); r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK, largepage, gfn, pfn, kvm_x86_ops->get_tdp_level()); spin_unlock(&vcpu->kvm->mmu_lock); return r; + +out_unlock: + spin_unlock(&vcpu->kvm->mmu_lock); + kvm_release_pfn_clean(pfn); + return 0; } static void nonpaging_free(struct kvm_vcpu *vcpu) @@ -1660,6 +1768,8 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, gfn &= ~(KVM_PAGES_PER_HPAGE-1); vcpu->arch.update_pte.largepage = 1; } + vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq; + /* implicit mb(), we'll read before PT lock is unlocked */ pfn = gfn_to_pfn(vcpu->kvm, gfn); up_read(¤t->mm->mmap_sem); @@ -1671,6 +1781,18 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, vcpu->arch.update_pte.pfn = pfn; } +static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn) +{ + u64 *spte = vcpu->arch.last_pte_updated; + + if (spte + && vcpu->arch.last_pte_gfn == gfn + && shadow_accessed_mask + && !(*spte & shadow_accessed_mask) + && is_shadow_present_pte(*spte)) + set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte); +} + void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, const u8 *new, int bytes) { @@ -1694,6 +1816,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa, pgprintk("%s: gpa %llx bytes %d\n", __func__, gpa, bytes); mmu_guess_page_from_pte_write(vcpu, gpa, new, bytes); spin_lock(&vcpu->kvm->mmu_lock); + kvm_mmu_access_page(vcpu, gfn); kvm_mmu_free_some_pages(vcpu); ++vcpu->kvm->stat.mmu_pte_write; kvm_mmu_audit(vcpu, "pre pte write"); @@ -1791,6 +1914,7 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva) spin_unlock(&vcpu->kvm->mmu_lock); return r; } +EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page_virt); void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu) { @@ -1847,6 +1971,12 @@ void kvm_enable_tdp(void) } EXPORT_SYMBOL_GPL(kvm_enable_tdp); +void kvm_disable_tdp(void) +{ + tdp_enabled = false; +} +EXPORT_SYMBOL_GPL(kvm_disable_tdp); + static void free_mmu_pages(struct kvm_vcpu *vcpu) { struct kvm_mmu_page *sp; @@ -1948,7 +2078,7 @@ void kvm_mmu_zap_all(struct kvm *kvm) kvm_flush_remote_tlbs(kvm); } -void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm) +static void kvm_mmu_remove_one_alloc_mmu_page(struct kvm *kvm) { struct kvm_mmu_page *page; @@ -1968,6 +2098,8 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask) list_for_each_entry(kvm, &vm_list, vm_list) { int npages; + if (!down_read_trylock(&kvm->slots_lock)) + continue; spin_lock(&kvm->mmu_lock); npages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages; @@ -1980,6 +2112,7 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask) nr_to_scan--; spin_unlock(&kvm->mmu_lock); + up_read(&kvm->slots_lock); } if (kvm_freed) list_move_tail(&kvm_freed->vm_list, &vm_list); |