1fe5db27dSBen Gardon // SPDX-License-Identifier: GPL-2.0 2fe5db27dSBen Gardon 302c00b3aSBen Gardon #include "mmu.h" 402c00b3aSBen Gardon #include "mmu_internal.h" 5bb18842eSBen Gardon #include "mmutrace.h" 62f2fad08SBen Gardon #include "tdp_iter.h" 7fe5db27dSBen Gardon #include "tdp_mmu.h" 802c00b3aSBen Gardon #include "spte.h" 9fe5db27dSBen Gardon 109a77daacSBen Gardon #include <asm/cmpxchg.h> 1133dd3574SBen Gardon #include <trace/events/kvm.h> 1233dd3574SBen Gardon 13fe5db27dSBen Gardon static bool __read_mostly tdp_mmu_enabled = false; 1495fb5b02SBen Gardon module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0644); 15fe5db27dSBen Gardon 16fe5db27dSBen Gardon /* Initializes the TDP MMU for the VM, if enabled. */ 17fe5db27dSBen Gardon void kvm_mmu_init_tdp_mmu(struct kvm *kvm) 18fe5db27dSBen Gardon { 19897218ffSPaolo Bonzini if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled)) 20fe5db27dSBen Gardon return; 21fe5db27dSBen Gardon 22fe5db27dSBen Gardon /* This should not be changed for the lifetime of the VM. */ 23fe5db27dSBen Gardon kvm->arch.tdp_mmu_enabled = true; 2402c00b3aSBen Gardon 2502c00b3aSBen Gardon INIT_LIST_HEAD(&kvm->arch.tdp_mmu_roots); 269a77daacSBen Gardon spin_lock_init(&kvm->arch.tdp_mmu_pages_lock); 2789c0fd49SBen Gardon INIT_LIST_HEAD(&kvm->arch.tdp_mmu_pages); 28fe5db27dSBen Gardon } 29fe5db27dSBen Gardon 30fe5db27dSBen Gardon void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm) 31fe5db27dSBen Gardon { 32fe5db27dSBen Gardon if (!kvm->arch.tdp_mmu_enabled) 33fe5db27dSBen Gardon return; 3402c00b3aSBen Gardon 3502c00b3aSBen Gardon WARN_ON(!list_empty(&kvm->arch.tdp_mmu_roots)); 367cca2d0bSBen Gardon 377cca2d0bSBen Gardon /* 387cca2d0bSBen Gardon * Ensure that all the outstanding RCU callbacks to free shadow pages 397cca2d0bSBen Gardon * can run before the VM is torn down. 407cca2d0bSBen Gardon */ 417cca2d0bSBen Gardon rcu_barrier(); 4202c00b3aSBen Gardon } 4302c00b3aSBen Gardon 44a889ea54SBen Gardon static void tdp_mmu_put_root(struct kvm *kvm, struct kvm_mmu_page *root) 45a889ea54SBen Gardon { 46a889ea54SBen Gardon if (kvm_mmu_put_root(kvm, root)) 47a889ea54SBen Gardon kvm_tdp_mmu_free_root(kvm, root); 48a889ea54SBen Gardon } 49a889ea54SBen Gardon 50a889ea54SBen Gardon static inline bool tdp_mmu_next_root_valid(struct kvm *kvm, 51a889ea54SBen Gardon struct kvm_mmu_page *root) 52a889ea54SBen Gardon { 53531810caSBen Gardon lockdep_assert_held_write(&kvm->mmu_lock); 54a889ea54SBen Gardon 55a889ea54SBen Gardon if (list_entry_is_head(root, &kvm->arch.tdp_mmu_roots, link)) 56a889ea54SBen Gardon return false; 57a889ea54SBen Gardon 58a889ea54SBen Gardon kvm_mmu_get_root(kvm, root); 59a889ea54SBen Gardon return true; 60a889ea54SBen Gardon 61a889ea54SBen Gardon } 62a889ea54SBen Gardon 63a889ea54SBen Gardon static inline struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm, 64a889ea54SBen Gardon struct kvm_mmu_page *root) 65a889ea54SBen Gardon { 66a889ea54SBen Gardon struct kvm_mmu_page *next_root; 67a889ea54SBen Gardon 68a889ea54SBen Gardon next_root = list_next_entry(root, link); 69a889ea54SBen Gardon tdp_mmu_put_root(kvm, root); 70a889ea54SBen Gardon return next_root; 71a889ea54SBen Gardon } 72a889ea54SBen Gardon 73a889ea54SBen Gardon /* 74a889ea54SBen Gardon * Note: this iterator gets and puts references to the roots it iterates over. 75a889ea54SBen Gardon * This makes it safe to release the MMU lock and yield within the loop, but 76a889ea54SBen Gardon * if exiting the loop early, the caller must drop the reference to the most 77a889ea54SBen Gardon * recent root. (Unless keeping a live reference is desirable.) 78a889ea54SBen Gardon */ 79a3f15bdaSSean Christopherson #define for_each_tdp_mmu_root_yield_safe(_kvm, _root, _as_id) \ 80a889ea54SBen Gardon for (_root = list_first_entry(&_kvm->arch.tdp_mmu_roots, \ 81a889ea54SBen Gardon typeof(*_root), link); \ 82a889ea54SBen Gardon tdp_mmu_next_root_valid(_kvm, _root); \ 83a3f15bdaSSean Christopherson _root = tdp_mmu_next_root(_kvm, _root)) \ 84a3f15bdaSSean Christopherson if (kvm_mmu_page_as_id(_root) != _as_id) { \ 85a3f15bdaSSean Christopherson } else 86a889ea54SBen Gardon 87a3f15bdaSSean Christopherson #define for_each_tdp_mmu_root(_kvm, _root, _as_id) \ 88a3f15bdaSSean Christopherson list_for_each_entry(_root, &_kvm->arch.tdp_mmu_roots, link) \ 89a3f15bdaSSean Christopherson if (kvm_mmu_page_as_id(_root) != _as_id) { \ 90a3f15bdaSSean Christopherson } else 9102c00b3aSBen Gardon 92faaf05b0SBen Gardon static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, 93a835429cSSean Christopherson gfn_t start, gfn_t end, bool can_yield, bool flush); 94faaf05b0SBen Gardon 9502c00b3aSBen Gardon void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root) 9602c00b3aSBen Gardon { 97339f5a7fSRick Edgecombe gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT); 98faaf05b0SBen Gardon 99531810caSBen Gardon lockdep_assert_held_write(&kvm->mmu_lock); 10002c00b3aSBen Gardon 10102c00b3aSBen Gardon WARN_ON(root->root_count); 10202c00b3aSBen Gardon WARN_ON(!root->tdp_mmu_page); 10302c00b3aSBen Gardon 10402c00b3aSBen Gardon list_del(&root->link); 10502c00b3aSBen Gardon 106a835429cSSean Christopherson zap_gfn_range(kvm, root, 0, max_gfn, false, false); 107faaf05b0SBen Gardon 10802c00b3aSBen Gardon free_page((unsigned long)root->spt); 10902c00b3aSBen Gardon kmem_cache_free(mmu_page_header_cache, root); 11002c00b3aSBen Gardon } 11102c00b3aSBen Gardon 11202c00b3aSBen Gardon static union kvm_mmu_page_role page_role_for_level(struct kvm_vcpu *vcpu, 11302c00b3aSBen Gardon int level) 11402c00b3aSBen Gardon { 11502c00b3aSBen Gardon union kvm_mmu_page_role role; 11602c00b3aSBen Gardon 11702c00b3aSBen Gardon role = vcpu->arch.mmu->mmu_role.base; 11802c00b3aSBen Gardon role.level = level; 11902c00b3aSBen Gardon role.direct = true; 12002c00b3aSBen Gardon role.gpte_is_8_bytes = true; 12102c00b3aSBen Gardon role.access = ACC_ALL; 12202c00b3aSBen Gardon 12302c00b3aSBen Gardon return role; 12402c00b3aSBen Gardon } 12502c00b3aSBen Gardon 12602c00b3aSBen Gardon static struct kvm_mmu_page *alloc_tdp_mmu_page(struct kvm_vcpu *vcpu, gfn_t gfn, 12702c00b3aSBen Gardon int level) 12802c00b3aSBen Gardon { 12902c00b3aSBen Gardon struct kvm_mmu_page *sp; 13002c00b3aSBen Gardon 13102c00b3aSBen Gardon sp = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_page_header_cache); 13202c00b3aSBen Gardon sp->spt = kvm_mmu_memory_cache_alloc(&vcpu->arch.mmu_shadow_page_cache); 13302c00b3aSBen Gardon set_page_private(virt_to_page(sp->spt), (unsigned long)sp); 13402c00b3aSBen Gardon 13502c00b3aSBen Gardon sp->role.word = page_role_for_level(vcpu, level).word; 13602c00b3aSBen Gardon sp->gfn = gfn; 13702c00b3aSBen Gardon sp->tdp_mmu_page = true; 13802c00b3aSBen Gardon 13933dd3574SBen Gardon trace_kvm_mmu_get_page(sp, true); 14033dd3574SBen Gardon 14102c00b3aSBen Gardon return sp; 14202c00b3aSBen Gardon } 14302c00b3aSBen Gardon 1446e6ec584SSean Christopherson hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu) 14502c00b3aSBen Gardon { 14602c00b3aSBen Gardon union kvm_mmu_page_role role; 14702c00b3aSBen Gardon struct kvm *kvm = vcpu->kvm; 14802c00b3aSBen Gardon struct kvm_mmu_page *root; 14902c00b3aSBen Gardon 1506e6ec584SSean Christopherson lockdep_assert_held_write(&kvm->mmu_lock); 15102c00b3aSBen Gardon 1526e6ec584SSean Christopherson role = page_role_for_level(vcpu, vcpu->arch.mmu->shadow_root_level); 15302c00b3aSBen Gardon 15402c00b3aSBen Gardon /* Check for an existing root before allocating a new one. */ 155a3f15bdaSSean Christopherson for_each_tdp_mmu_root(kvm, root, kvm_mmu_role_as_id(role)) { 15602c00b3aSBen Gardon if (root->role.word == role.word) { 15702c00b3aSBen Gardon kvm_mmu_get_root(kvm, root); 1586e6ec584SSean Christopherson goto out; 15902c00b3aSBen Gardon } 16002c00b3aSBen Gardon } 16102c00b3aSBen Gardon 16202c00b3aSBen Gardon root = alloc_tdp_mmu_page(vcpu, 0, vcpu->arch.mmu->shadow_root_level); 16302c00b3aSBen Gardon root->root_count = 1; 16402c00b3aSBen Gardon 16502c00b3aSBen Gardon list_add(&root->link, &kvm->arch.tdp_mmu_roots); 16602c00b3aSBen Gardon 1676e6ec584SSean Christopherson out: 16802c00b3aSBen Gardon return __pa(root->spt); 169fe5db27dSBen Gardon } 1702f2fad08SBen Gardon 1717cca2d0bSBen Gardon static void tdp_mmu_free_sp(struct kvm_mmu_page *sp) 1727cca2d0bSBen Gardon { 1737cca2d0bSBen Gardon free_page((unsigned long)sp->spt); 1747cca2d0bSBen Gardon kmem_cache_free(mmu_page_header_cache, sp); 1757cca2d0bSBen Gardon } 1767cca2d0bSBen Gardon 1777cca2d0bSBen Gardon /* 1787cca2d0bSBen Gardon * This is called through call_rcu in order to free TDP page table memory 1797cca2d0bSBen Gardon * safely with respect to other kernel threads that may be operating on 1807cca2d0bSBen Gardon * the memory. 1817cca2d0bSBen Gardon * By only accessing TDP MMU page table memory in an RCU read critical 1827cca2d0bSBen Gardon * section, and freeing it after a grace period, lockless access to that 1837cca2d0bSBen Gardon * memory won't use it after it is freed. 1847cca2d0bSBen Gardon */ 1857cca2d0bSBen Gardon static void tdp_mmu_free_sp_rcu_callback(struct rcu_head *head) 1867cca2d0bSBen Gardon { 1877cca2d0bSBen Gardon struct kvm_mmu_page *sp = container_of(head, struct kvm_mmu_page, 1887cca2d0bSBen Gardon rcu_head); 1897cca2d0bSBen Gardon 1907cca2d0bSBen Gardon tdp_mmu_free_sp(sp); 1917cca2d0bSBen Gardon } 1927cca2d0bSBen Gardon 1932f2fad08SBen Gardon static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, 1949a77daacSBen Gardon u64 old_spte, u64 new_spte, int level, 1959a77daacSBen Gardon bool shared); 1962f2fad08SBen Gardon 197f8e14497SBen Gardon static void handle_changed_spte_acc_track(u64 old_spte, u64 new_spte, int level) 198f8e14497SBen Gardon { 199f8e14497SBen Gardon if (!is_shadow_present_pte(old_spte) || !is_last_spte(old_spte, level)) 200f8e14497SBen Gardon return; 201f8e14497SBen Gardon 202f8e14497SBen Gardon if (is_accessed_spte(old_spte) && 20364bb2769SSean Christopherson (!is_shadow_present_pte(new_spte) || !is_accessed_spte(new_spte) || 20464bb2769SSean Christopherson spte_to_pfn(old_spte) != spte_to_pfn(new_spte))) 205f8e14497SBen Gardon kvm_set_pfn_accessed(spte_to_pfn(old_spte)); 206f8e14497SBen Gardon } 207f8e14497SBen Gardon 208a6a0b05dSBen Gardon static void handle_changed_spte_dirty_log(struct kvm *kvm, int as_id, gfn_t gfn, 209a6a0b05dSBen Gardon u64 old_spte, u64 new_spte, int level) 210a6a0b05dSBen Gardon { 211a6a0b05dSBen Gardon bool pfn_changed; 212a6a0b05dSBen Gardon struct kvm_memory_slot *slot; 213a6a0b05dSBen Gardon 214a6a0b05dSBen Gardon if (level > PG_LEVEL_4K) 215a6a0b05dSBen Gardon return; 216a6a0b05dSBen Gardon 217a6a0b05dSBen Gardon pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); 218a6a0b05dSBen Gardon 219a6a0b05dSBen Gardon if ((!is_writable_pte(old_spte) || pfn_changed) && 220a6a0b05dSBen Gardon is_writable_pte(new_spte)) { 221a6a0b05dSBen Gardon slot = __gfn_to_memslot(__kvm_memslots(kvm, as_id), gfn); 222fb04a1edSPeter Xu mark_page_dirty_in_slot(kvm, slot, gfn); 223a6a0b05dSBen Gardon } 224a6a0b05dSBen Gardon } 225a6a0b05dSBen Gardon 2262f2fad08SBen Gardon /** 227a9442f59SBen Gardon * tdp_mmu_link_page - Add a new page to the list of pages used by the TDP MMU 228a9442f59SBen Gardon * 229a9442f59SBen Gardon * @kvm: kvm instance 230a9442f59SBen Gardon * @sp: the new page 2319a77daacSBen Gardon * @shared: This operation may not be running under the exclusive use of 2329a77daacSBen Gardon * the MMU lock and the operation must synchronize with other 2339a77daacSBen Gardon * threads that might be adding or removing pages. 234a9442f59SBen Gardon * @account_nx: This page replaces a NX large page and should be marked for 235a9442f59SBen Gardon * eventual reclaim. 236a9442f59SBen Gardon */ 237a9442f59SBen Gardon static void tdp_mmu_link_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2389a77daacSBen Gardon bool shared, bool account_nx) 239a9442f59SBen Gardon { 2409a77daacSBen Gardon if (shared) 2419a77daacSBen Gardon spin_lock(&kvm->arch.tdp_mmu_pages_lock); 2429a77daacSBen Gardon else 243a9442f59SBen Gardon lockdep_assert_held_write(&kvm->mmu_lock); 244a9442f59SBen Gardon 245a9442f59SBen Gardon list_add(&sp->link, &kvm->arch.tdp_mmu_pages); 246a9442f59SBen Gardon if (account_nx) 247a9442f59SBen Gardon account_huge_nx_page(kvm, sp); 2489a77daacSBen Gardon 2499a77daacSBen Gardon if (shared) 2509a77daacSBen Gardon spin_unlock(&kvm->arch.tdp_mmu_pages_lock); 251a9442f59SBen Gardon } 252a9442f59SBen Gardon 253a9442f59SBen Gardon /** 254a9442f59SBen Gardon * tdp_mmu_unlink_page - Remove page from the list of pages used by the TDP MMU 255a9442f59SBen Gardon * 256a9442f59SBen Gardon * @kvm: kvm instance 257a9442f59SBen Gardon * @sp: the page to be removed 2589a77daacSBen Gardon * @shared: This operation may not be running under the exclusive use of 2599a77daacSBen Gardon * the MMU lock and the operation must synchronize with other 2609a77daacSBen Gardon * threads that might be adding or removing pages. 261a9442f59SBen Gardon */ 2629a77daacSBen Gardon static void tdp_mmu_unlink_page(struct kvm *kvm, struct kvm_mmu_page *sp, 2639a77daacSBen Gardon bool shared) 264a9442f59SBen Gardon { 2659a77daacSBen Gardon if (shared) 2669a77daacSBen Gardon spin_lock(&kvm->arch.tdp_mmu_pages_lock); 2679a77daacSBen Gardon else 268a9442f59SBen Gardon lockdep_assert_held_write(&kvm->mmu_lock); 269a9442f59SBen Gardon 270a9442f59SBen Gardon list_del(&sp->link); 271a9442f59SBen Gardon if (sp->lpage_disallowed) 272a9442f59SBen Gardon unaccount_huge_nx_page(kvm, sp); 2739a77daacSBen Gardon 2749a77daacSBen Gardon if (shared) 2759a77daacSBen Gardon spin_unlock(&kvm->arch.tdp_mmu_pages_lock); 276a9442f59SBen Gardon } 277a9442f59SBen Gardon 278a9442f59SBen Gardon /** 279a066e61fSBen Gardon * handle_removed_tdp_mmu_page - handle a pt removed from the TDP structure 280a066e61fSBen Gardon * 281a066e61fSBen Gardon * @kvm: kvm instance 282a066e61fSBen Gardon * @pt: the page removed from the paging structure 2839a77daacSBen Gardon * @shared: This operation may not be running under the exclusive use 2849a77daacSBen Gardon * of the MMU lock and the operation must synchronize with other 2859a77daacSBen Gardon * threads that might be modifying SPTEs. 286a066e61fSBen Gardon * 287a066e61fSBen Gardon * Given a page table that has been removed from the TDP paging structure, 288a066e61fSBen Gardon * iterates through the page table to clear SPTEs and free child page tables. 28970fb3e41SBen Gardon * 29070fb3e41SBen Gardon * Note that pt is passed in as a tdp_ptep_t, but it does not need RCU 29170fb3e41SBen Gardon * protection. Since this thread removed it from the paging structure, 29270fb3e41SBen Gardon * this thread will be responsible for ensuring the page is freed. Hence the 29370fb3e41SBen Gardon * early rcu_dereferences in the function. 294a066e61fSBen Gardon */ 29570fb3e41SBen Gardon static void handle_removed_tdp_mmu_page(struct kvm *kvm, tdp_ptep_t pt, 2969a77daacSBen Gardon bool shared) 297a066e61fSBen Gardon { 29870fb3e41SBen Gardon struct kvm_mmu_page *sp = sptep_to_sp(rcu_dereference(pt)); 299a066e61fSBen Gardon int level = sp->role.level; 300e25f0e0cSBen Gardon gfn_t base_gfn = sp->gfn; 301a066e61fSBen Gardon u64 old_child_spte; 3029a77daacSBen Gardon u64 *sptep; 303e25f0e0cSBen Gardon gfn_t gfn; 304a066e61fSBen Gardon int i; 305a066e61fSBen Gardon 306a066e61fSBen Gardon trace_kvm_mmu_prepare_zap_page(sp); 307a066e61fSBen Gardon 3089a77daacSBen Gardon tdp_mmu_unlink_page(kvm, sp, shared); 309a066e61fSBen Gardon 310a066e61fSBen Gardon for (i = 0; i < PT64_ENT_PER_PAGE; i++) { 31170fb3e41SBen Gardon sptep = rcu_dereference(pt) + i; 312e25f0e0cSBen Gardon gfn = base_gfn + (i * KVM_PAGES_PER_HPAGE(level - 1)); 3139a77daacSBen Gardon 3149a77daacSBen Gardon if (shared) { 315e25f0e0cSBen Gardon /* 316e25f0e0cSBen Gardon * Set the SPTE to a nonpresent value that other 317e25f0e0cSBen Gardon * threads will not overwrite. If the SPTE was 318e25f0e0cSBen Gardon * already marked as removed then another thread 319e25f0e0cSBen Gardon * handling a page fault could overwrite it, so 320e25f0e0cSBen Gardon * set the SPTE until it is set from some other 321e25f0e0cSBen Gardon * value to the removed SPTE value. 322e25f0e0cSBen Gardon */ 323e25f0e0cSBen Gardon for (;;) { 324e25f0e0cSBen Gardon old_child_spte = xchg(sptep, REMOVED_SPTE); 325e25f0e0cSBen Gardon if (!is_removed_spte(old_child_spte)) 326e25f0e0cSBen Gardon break; 327e25f0e0cSBen Gardon cpu_relax(); 328e25f0e0cSBen Gardon } 3299a77daacSBen Gardon } else { 3308df9f1afSSean Christopherson /* 3318df9f1afSSean Christopherson * If the SPTE is not MMU-present, there is no backing 3328df9f1afSSean Christopherson * page associated with the SPTE and so no side effects 3338df9f1afSSean Christopherson * that need to be recorded, and exclusive ownership of 3348df9f1afSSean Christopherson * mmu_lock ensures the SPTE can't be made present. 3358df9f1afSSean Christopherson * Note, zapping MMIO SPTEs is also unnecessary as they 3368df9f1afSSean Christopherson * are guarded by the memslots generation, not by being 3378df9f1afSSean Christopherson * unreachable. 3388df9f1afSSean Christopherson */ 3399a77daacSBen Gardon old_child_spte = READ_ONCE(*sptep); 3408df9f1afSSean Christopherson if (!is_shadow_present_pte(old_child_spte)) 3418df9f1afSSean Christopherson continue; 342e25f0e0cSBen Gardon 343e25f0e0cSBen Gardon /* 344e25f0e0cSBen Gardon * Marking the SPTE as a removed SPTE is not 345e25f0e0cSBen Gardon * strictly necessary here as the MMU lock will 346e25f0e0cSBen Gardon * stop other threads from concurrently modifying 347e25f0e0cSBen Gardon * this SPTE. Using the removed SPTE value keeps 348e25f0e0cSBen Gardon * the two branches consistent and simplifies 349e25f0e0cSBen Gardon * the function. 350e25f0e0cSBen Gardon */ 351e25f0e0cSBen Gardon WRITE_ONCE(*sptep, REMOVED_SPTE); 3529a77daacSBen Gardon } 353e25f0e0cSBen Gardon handle_changed_spte(kvm, kvm_mmu_page_as_id(sp), gfn, 354e25f0e0cSBen Gardon old_child_spte, REMOVED_SPTE, level - 1, 355e25f0e0cSBen Gardon shared); 356a066e61fSBen Gardon } 357a066e61fSBen Gardon 358a066e61fSBen Gardon kvm_flush_remote_tlbs_with_address(kvm, gfn, 359a066e61fSBen Gardon KVM_PAGES_PER_HPAGE(level)); 360a066e61fSBen Gardon 3617cca2d0bSBen Gardon call_rcu(&sp->rcu_head, tdp_mmu_free_sp_rcu_callback); 362a066e61fSBen Gardon } 363a066e61fSBen Gardon 364a066e61fSBen Gardon /** 3652f2fad08SBen Gardon * handle_changed_spte - handle bookkeeping associated with an SPTE change 3662f2fad08SBen Gardon * @kvm: kvm instance 3672f2fad08SBen Gardon * @as_id: the address space of the paging structure the SPTE was a part of 3682f2fad08SBen Gardon * @gfn: the base GFN that was mapped by the SPTE 3692f2fad08SBen Gardon * @old_spte: The value of the SPTE before the change 3702f2fad08SBen Gardon * @new_spte: The value of the SPTE after the change 3712f2fad08SBen Gardon * @level: the level of the PT the SPTE is part of in the paging structure 3729a77daacSBen Gardon * @shared: This operation may not be running under the exclusive use of 3739a77daacSBen Gardon * the MMU lock and the operation must synchronize with other 3749a77daacSBen Gardon * threads that might be modifying SPTEs. 3752f2fad08SBen Gardon * 3762f2fad08SBen Gardon * Handle bookkeeping that might result from the modification of a SPTE. 3772f2fad08SBen Gardon * This function must be called for all TDP SPTE modifications. 3782f2fad08SBen Gardon */ 3792f2fad08SBen Gardon static void __handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, 3809a77daacSBen Gardon u64 old_spte, u64 new_spte, int level, 3819a77daacSBen Gardon bool shared) 3822f2fad08SBen Gardon { 3832f2fad08SBen Gardon bool was_present = is_shadow_present_pte(old_spte); 3842f2fad08SBen Gardon bool is_present = is_shadow_present_pte(new_spte); 3852f2fad08SBen Gardon bool was_leaf = was_present && is_last_spte(old_spte, level); 3862f2fad08SBen Gardon bool is_leaf = is_present && is_last_spte(new_spte, level); 3872f2fad08SBen Gardon bool pfn_changed = spte_to_pfn(old_spte) != spte_to_pfn(new_spte); 3882f2fad08SBen Gardon 3892f2fad08SBen Gardon WARN_ON(level > PT64_ROOT_MAX_LEVEL); 3902f2fad08SBen Gardon WARN_ON(level < PG_LEVEL_4K); 391764388ceSSean Christopherson WARN_ON(gfn & (KVM_PAGES_PER_HPAGE(level) - 1)); 3922f2fad08SBen Gardon 3932f2fad08SBen Gardon /* 3942f2fad08SBen Gardon * If this warning were to trigger it would indicate that there was a 3952f2fad08SBen Gardon * missing MMU notifier or a race with some notifier handler. 3962f2fad08SBen Gardon * A present, leaf SPTE should never be directly replaced with another 3972f2fad08SBen Gardon * present leaf SPTE pointing to a differnt PFN. A notifier handler 3982f2fad08SBen Gardon * should be zapping the SPTE before the main MM's page table is 3992f2fad08SBen Gardon * changed, or the SPTE should be zeroed, and the TLBs flushed by the 4002f2fad08SBen Gardon * thread before replacement. 4012f2fad08SBen Gardon */ 4022f2fad08SBen Gardon if (was_leaf && is_leaf && pfn_changed) { 4032f2fad08SBen Gardon pr_err("Invalid SPTE change: cannot replace a present leaf\n" 4042f2fad08SBen Gardon "SPTE with another present leaf SPTE mapping a\n" 4052f2fad08SBen Gardon "different PFN!\n" 4062f2fad08SBen Gardon "as_id: %d gfn: %llx old_spte: %llx new_spte: %llx level: %d", 4072f2fad08SBen Gardon as_id, gfn, old_spte, new_spte, level); 4082f2fad08SBen Gardon 4092f2fad08SBen Gardon /* 4102f2fad08SBen Gardon * Crash the host to prevent error propagation and guest data 4112f2fad08SBen Gardon * courruption. 4122f2fad08SBen Gardon */ 4132f2fad08SBen Gardon BUG(); 4142f2fad08SBen Gardon } 4152f2fad08SBen Gardon 4162f2fad08SBen Gardon if (old_spte == new_spte) 4172f2fad08SBen Gardon return; 4182f2fad08SBen Gardon 419b9a98c34SBen Gardon trace_kvm_tdp_mmu_spte_changed(as_id, gfn, level, old_spte, new_spte); 420b9a98c34SBen Gardon 4212f2fad08SBen Gardon /* 4222f2fad08SBen Gardon * The only times a SPTE should be changed from a non-present to 4232f2fad08SBen Gardon * non-present state is when an MMIO entry is installed/modified/ 4242f2fad08SBen Gardon * removed. In that case, there is nothing to do here. 4252f2fad08SBen Gardon */ 4262f2fad08SBen Gardon if (!was_present && !is_present) { 4272f2fad08SBen Gardon /* 42808f07c80SBen Gardon * If this change does not involve a MMIO SPTE or removed SPTE, 42908f07c80SBen Gardon * it is unexpected. Log the change, though it should not 43008f07c80SBen Gardon * impact the guest since both the former and current SPTEs 43108f07c80SBen Gardon * are nonpresent. 4322f2fad08SBen Gardon */ 43308f07c80SBen Gardon if (WARN_ON(!is_mmio_spte(old_spte) && 43408f07c80SBen Gardon !is_mmio_spte(new_spte) && 43508f07c80SBen Gardon !is_removed_spte(new_spte))) 4362f2fad08SBen Gardon pr_err("Unexpected SPTE change! Nonpresent SPTEs\n" 4372f2fad08SBen Gardon "should not be replaced with another,\n" 4382f2fad08SBen Gardon "different nonpresent SPTE, unless one or both\n" 43908f07c80SBen Gardon "are MMIO SPTEs, or the new SPTE is\n" 44008f07c80SBen Gardon "a temporary removed SPTE.\n" 4412f2fad08SBen Gardon "as_id: %d gfn: %llx old_spte: %llx new_spte: %llx level: %d", 4422f2fad08SBen Gardon as_id, gfn, old_spte, new_spte, level); 4432f2fad08SBen Gardon return; 4442f2fad08SBen Gardon } 4452f2fad08SBen Gardon 4462f2fad08SBen Gardon 4472f2fad08SBen Gardon if (was_leaf && is_dirty_spte(old_spte) && 44864bb2769SSean Christopherson (!is_present || !is_dirty_spte(new_spte) || pfn_changed)) 4492f2fad08SBen Gardon kvm_set_pfn_dirty(spte_to_pfn(old_spte)); 4502f2fad08SBen Gardon 4512f2fad08SBen Gardon /* 4522f2fad08SBen Gardon * Recursively handle child PTs if the change removed a subtree from 4532f2fad08SBen Gardon * the paging structure. 4542f2fad08SBen Gardon */ 455a066e61fSBen Gardon if (was_present && !was_leaf && (pfn_changed || !is_present)) 456a066e61fSBen Gardon handle_removed_tdp_mmu_page(kvm, 4579a77daacSBen Gardon spte_to_child_pt(old_spte, level), shared); 4582f2fad08SBen Gardon } 4592f2fad08SBen Gardon 4602f2fad08SBen Gardon static void handle_changed_spte(struct kvm *kvm, int as_id, gfn_t gfn, 4619a77daacSBen Gardon u64 old_spte, u64 new_spte, int level, 4629a77daacSBen Gardon bool shared) 4632f2fad08SBen Gardon { 4649a77daacSBen Gardon __handle_changed_spte(kvm, as_id, gfn, old_spte, new_spte, level, 4659a77daacSBen Gardon shared); 466f8e14497SBen Gardon handle_changed_spte_acc_track(old_spte, new_spte, level); 467a6a0b05dSBen Gardon handle_changed_spte_dirty_log(kvm, as_id, gfn, old_spte, 468a6a0b05dSBen Gardon new_spte, level); 4692f2fad08SBen Gardon } 470faaf05b0SBen Gardon 471fe43fa2fSBen Gardon /* 4729a77daacSBen Gardon * tdp_mmu_set_spte_atomic - Set a TDP MMU SPTE atomically and handle the 4739a77daacSBen Gardon * associated bookkeeping 4749a77daacSBen Gardon * 4759a77daacSBen Gardon * @kvm: kvm instance 4769a77daacSBen Gardon * @iter: a tdp_iter instance currently on the SPTE that should be set 4779a77daacSBen Gardon * @new_spte: The value the SPTE should be set to 4789a77daacSBen Gardon * Returns: true if the SPTE was set, false if it was not. If false is returned, 4799a77daacSBen Gardon * this function will have no side-effects. 4809a77daacSBen Gardon */ 4819a77daacSBen Gardon static inline bool tdp_mmu_set_spte_atomic(struct kvm *kvm, 4829a77daacSBen Gardon struct tdp_iter *iter, 4839a77daacSBen Gardon u64 new_spte) 4849a77daacSBen Gardon { 4859a77daacSBen Gardon lockdep_assert_held_read(&kvm->mmu_lock); 4869a77daacSBen Gardon 48708f07c80SBen Gardon /* 48808f07c80SBen Gardon * Do not change removed SPTEs. Only the thread that froze the SPTE 48908f07c80SBen Gardon * may modify it. 49008f07c80SBen Gardon */ 4917a51393aSSean Christopherson if (is_removed_spte(iter->old_spte)) 49208f07c80SBen Gardon return false; 49308f07c80SBen Gardon 4949a77daacSBen Gardon if (cmpxchg64(rcu_dereference(iter->sptep), iter->old_spte, 4959a77daacSBen Gardon new_spte) != iter->old_spte) 4969a77daacSBen Gardon return false; 4979a77daacSBen Gardon 49808889894SSean Christopherson handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte, 49908889894SSean Christopherson new_spte, iter->level, true); 5009a77daacSBen Gardon 5019a77daacSBen Gardon return true; 5029a77daacSBen Gardon } 5039a77daacSBen Gardon 50408f07c80SBen Gardon static inline bool tdp_mmu_zap_spte_atomic(struct kvm *kvm, 50508f07c80SBen Gardon struct tdp_iter *iter) 50608f07c80SBen Gardon { 50708f07c80SBen Gardon /* 50808f07c80SBen Gardon * Freeze the SPTE by setting it to a special, 50908f07c80SBen Gardon * non-present value. This will stop other threads from 51008f07c80SBen Gardon * immediately installing a present entry in its place 51108f07c80SBen Gardon * before the TLBs are flushed. 51208f07c80SBen Gardon */ 51308f07c80SBen Gardon if (!tdp_mmu_set_spte_atomic(kvm, iter, REMOVED_SPTE)) 51408f07c80SBen Gardon return false; 51508f07c80SBen Gardon 51608f07c80SBen Gardon kvm_flush_remote_tlbs_with_address(kvm, iter->gfn, 51708f07c80SBen Gardon KVM_PAGES_PER_HPAGE(iter->level)); 51808f07c80SBen Gardon 51908f07c80SBen Gardon /* 52008f07c80SBen Gardon * No other thread can overwrite the removed SPTE as they 52108f07c80SBen Gardon * must either wait on the MMU lock or use 52208f07c80SBen Gardon * tdp_mmu_set_spte_atomic which will not overrite the 52308f07c80SBen Gardon * special removed SPTE value. No bookkeeping is needed 52408f07c80SBen Gardon * here since the SPTE is going from non-present 52508f07c80SBen Gardon * to non-present. 52608f07c80SBen Gardon */ 52714f6fec2SBen Gardon WRITE_ONCE(*rcu_dereference(iter->sptep), 0); 52808f07c80SBen Gardon 52908f07c80SBen Gardon return true; 53008f07c80SBen Gardon } 53108f07c80SBen Gardon 5329a77daacSBen Gardon 5339a77daacSBen Gardon /* 534fe43fa2fSBen Gardon * __tdp_mmu_set_spte - Set a TDP MMU SPTE and handle the associated bookkeeping 535fe43fa2fSBen Gardon * @kvm: kvm instance 536fe43fa2fSBen Gardon * @iter: a tdp_iter instance currently on the SPTE that should be set 537fe43fa2fSBen Gardon * @new_spte: The value the SPTE should be set to 538fe43fa2fSBen Gardon * @record_acc_track: Notify the MM subsystem of changes to the accessed state 539fe43fa2fSBen Gardon * of the page. Should be set unless handling an MMU 540fe43fa2fSBen Gardon * notifier for access tracking. Leaving record_acc_track 541fe43fa2fSBen Gardon * unset in that case prevents page accesses from being 542fe43fa2fSBen Gardon * double counted. 543fe43fa2fSBen Gardon * @record_dirty_log: Record the page as dirty in the dirty bitmap if 544fe43fa2fSBen Gardon * appropriate for the change being made. Should be set 545fe43fa2fSBen Gardon * unless performing certain dirty logging operations. 546fe43fa2fSBen Gardon * Leaving record_dirty_log unset in that case prevents page 547fe43fa2fSBen Gardon * writes from being double counted. 548fe43fa2fSBen Gardon */ 549f8e14497SBen Gardon static inline void __tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter, 550a6a0b05dSBen Gardon u64 new_spte, bool record_acc_track, 551a6a0b05dSBen Gardon bool record_dirty_log) 552faaf05b0SBen Gardon { 553531810caSBen Gardon lockdep_assert_held_write(&kvm->mmu_lock); 5543a9a4aa5SBen Gardon 55508f07c80SBen Gardon /* 55608f07c80SBen Gardon * No thread should be using this function to set SPTEs to the 55708f07c80SBen Gardon * temporary removed SPTE value. 55808f07c80SBen Gardon * If operating under the MMU lock in read mode, tdp_mmu_set_spte_atomic 55908f07c80SBen Gardon * should be used. If operating under the MMU lock in write mode, the 56008f07c80SBen Gardon * use of the removed SPTE should not be necessary. 56108f07c80SBen Gardon */ 5627a51393aSSean Christopherson WARN_ON(is_removed_spte(iter->old_spte)); 56308f07c80SBen Gardon 5647cca2d0bSBen Gardon WRITE_ONCE(*rcu_dereference(iter->sptep), new_spte); 565faaf05b0SBen Gardon 56608889894SSean Christopherson __handle_changed_spte(kvm, iter->as_id, iter->gfn, iter->old_spte, 56708889894SSean Christopherson new_spte, iter->level, false); 568f8e14497SBen Gardon if (record_acc_track) 569f8e14497SBen Gardon handle_changed_spte_acc_track(iter->old_spte, new_spte, 570f8e14497SBen Gardon iter->level); 571a6a0b05dSBen Gardon if (record_dirty_log) 57208889894SSean Christopherson handle_changed_spte_dirty_log(kvm, iter->as_id, iter->gfn, 573a6a0b05dSBen Gardon iter->old_spte, new_spte, 574a6a0b05dSBen Gardon iter->level); 575f8e14497SBen Gardon } 576f8e14497SBen Gardon 577f8e14497SBen Gardon static inline void tdp_mmu_set_spte(struct kvm *kvm, struct tdp_iter *iter, 578f8e14497SBen Gardon u64 new_spte) 579f8e14497SBen Gardon { 580a6a0b05dSBen Gardon __tdp_mmu_set_spte(kvm, iter, new_spte, true, true); 581f8e14497SBen Gardon } 582f8e14497SBen Gardon 583f8e14497SBen Gardon static inline void tdp_mmu_set_spte_no_acc_track(struct kvm *kvm, 584f8e14497SBen Gardon struct tdp_iter *iter, 585f8e14497SBen Gardon u64 new_spte) 586f8e14497SBen Gardon { 587a6a0b05dSBen Gardon __tdp_mmu_set_spte(kvm, iter, new_spte, false, true); 588a6a0b05dSBen Gardon } 589a6a0b05dSBen Gardon 590a6a0b05dSBen Gardon static inline void tdp_mmu_set_spte_no_dirty_log(struct kvm *kvm, 591a6a0b05dSBen Gardon struct tdp_iter *iter, 592a6a0b05dSBen Gardon u64 new_spte) 593a6a0b05dSBen Gardon { 594a6a0b05dSBen Gardon __tdp_mmu_set_spte(kvm, iter, new_spte, true, false); 595faaf05b0SBen Gardon } 596faaf05b0SBen Gardon 597faaf05b0SBen Gardon #define tdp_root_for_each_pte(_iter, _root, _start, _end) \ 598faaf05b0SBen Gardon for_each_tdp_pte(_iter, _root->spt, _root->role.level, _start, _end) 599faaf05b0SBen Gardon 600f8e14497SBen Gardon #define tdp_root_for_each_leaf_pte(_iter, _root, _start, _end) \ 601f8e14497SBen Gardon tdp_root_for_each_pte(_iter, _root, _start, _end) \ 602f8e14497SBen Gardon if (!is_shadow_present_pte(_iter.old_spte) || \ 603f8e14497SBen Gardon !is_last_spte(_iter.old_spte, _iter.level)) \ 604f8e14497SBen Gardon continue; \ 605f8e14497SBen Gardon else 606f8e14497SBen Gardon 607bb18842eSBen Gardon #define tdp_mmu_for_each_pte(_iter, _mmu, _start, _end) \ 608bb18842eSBen Gardon for_each_tdp_pte(_iter, __va(_mmu->root_hpa), \ 609bb18842eSBen Gardon _mmu->shadow_root_level, _start, _end) 610bb18842eSBen Gardon 611faaf05b0SBen Gardon /* 612e28a436cSBen Gardon * Yield if the MMU lock is contended or this thread needs to return control 613e28a436cSBen Gardon * to the scheduler. 614e28a436cSBen Gardon * 615e139a34eSBen Gardon * If this function should yield and flush is set, it will perform a remote 616e139a34eSBen Gardon * TLB flush before yielding. 617e139a34eSBen Gardon * 618e28a436cSBen Gardon * If this function yields, it will also reset the tdp_iter's walk over the 619ed5e484bSBen Gardon * paging structure and the calling function should skip to the next 620ed5e484bSBen Gardon * iteration to allow the iterator to continue its traversal from the 621ed5e484bSBen Gardon * paging structure root. 622e28a436cSBen Gardon * 623e28a436cSBen Gardon * Return true if this function yielded and the iterator's traversal was reset. 624e28a436cSBen Gardon * Return false if a yield was not needed. 625e28a436cSBen Gardon */ 626e139a34eSBen Gardon static inline bool tdp_mmu_iter_cond_resched(struct kvm *kvm, 627e139a34eSBen Gardon struct tdp_iter *iter, bool flush) 628a6a0b05dSBen Gardon { 629ed5e484bSBen Gardon /* Ensure forward progress has been made before yielding. */ 630ed5e484bSBen Gardon if (iter->next_last_level_gfn == iter->yielded_gfn) 631ed5e484bSBen Gardon return false; 632ed5e484bSBen Gardon 633531810caSBen Gardon if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { 6347cca2d0bSBen Gardon rcu_read_unlock(); 6357cca2d0bSBen Gardon 636e139a34eSBen Gardon if (flush) 637e139a34eSBen Gardon kvm_flush_remote_tlbs(kvm); 638e139a34eSBen Gardon 639531810caSBen Gardon cond_resched_rwlock_write(&kvm->mmu_lock); 6407cca2d0bSBen Gardon rcu_read_lock(); 641ed5e484bSBen Gardon 642ed5e484bSBen Gardon WARN_ON(iter->gfn > iter->next_last_level_gfn); 643ed5e484bSBen Gardon 644b601c3bcSBen Gardon tdp_iter_restart(iter); 645ed5e484bSBen Gardon 646e28a436cSBen Gardon return true; 647a6a0b05dSBen Gardon } 648e28a436cSBen Gardon 649e28a436cSBen Gardon return false; 650a6a0b05dSBen Gardon } 651a6a0b05dSBen Gardon 652faaf05b0SBen Gardon /* 653faaf05b0SBen Gardon * Tears down the mappings for the range of gfns, [start, end), and frees the 654faaf05b0SBen Gardon * non-root pages mapping GFNs strictly within that range. Returns true if 655faaf05b0SBen Gardon * SPTEs have been cleared and a TLB flush is needed before releasing the 656faaf05b0SBen Gardon * MMU lock. 657063afacdSBen Gardon * If can_yield is true, will release the MMU lock and reschedule if the 658063afacdSBen Gardon * scheduler needs the CPU or there is contention on the MMU lock. If this 659063afacdSBen Gardon * function cannot yield, it will not release the MMU lock or reschedule and 660063afacdSBen Gardon * the caller must ensure it does not supply too large a GFN range, or the 661a835429cSSean Christopherson * operation can cause a soft lockup. Note, in some use cases a flush may be 662a835429cSSean Christopherson * required by prior actions. Ensure the pending flush is performed prior to 663a835429cSSean Christopherson * yielding. 664faaf05b0SBen Gardon */ 665faaf05b0SBen Gardon static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, 666a835429cSSean Christopherson gfn_t start, gfn_t end, bool can_yield, bool flush) 667faaf05b0SBen Gardon { 668faaf05b0SBen Gardon struct tdp_iter iter; 669faaf05b0SBen Gardon 6707cca2d0bSBen Gardon rcu_read_lock(); 6717cca2d0bSBen Gardon 672faaf05b0SBen Gardon tdp_root_for_each_pte(iter, root, start, end) { 6731af4a960SBen Gardon if (can_yield && 674a835429cSSean Christopherson tdp_mmu_iter_cond_resched(kvm, &iter, flush)) { 675a835429cSSean Christopherson flush = false; 6761af4a960SBen Gardon continue; 6771af4a960SBen Gardon } 6781af4a960SBen Gardon 679faaf05b0SBen Gardon if (!is_shadow_present_pte(iter.old_spte)) 680faaf05b0SBen Gardon continue; 681faaf05b0SBen Gardon 682faaf05b0SBen Gardon /* 683faaf05b0SBen Gardon * If this is a non-last-level SPTE that covers a larger range 684faaf05b0SBen Gardon * than should be zapped, continue, and zap the mappings at a 685faaf05b0SBen Gardon * lower level. 686faaf05b0SBen Gardon */ 687faaf05b0SBen Gardon if ((iter.gfn < start || 688faaf05b0SBen Gardon iter.gfn + KVM_PAGES_PER_HPAGE(iter.level) > end) && 689faaf05b0SBen Gardon !is_last_spte(iter.old_spte, iter.level)) 690faaf05b0SBen Gardon continue; 691faaf05b0SBen Gardon 692faaf05b0SBen Gardon tdp_mmu_set_spte(kvm, &iter, 0); 693a835429cSSean Christopherson flush = true; 694faaf05b0SBen Gardon } 6957cca2d0bSBen Gardon 6967cca2d0bSBen Gardon rcu_read_unlock(); 697a835429cSSean Christopherson return flush; 698faaf05b0SBen Gardon } 699faaf05b0SBen Gardon 700faaf05b0SBen Gardon /* 701faaf05b0SBen Gardon * Tears down the mappings for the range of gfns, [start, end), and frees the 702faaf05b0SBen Gardon * non-root pages mapping GFNs strictly within that range. Returns true if 703faaf05b0SBen Gardon * SPTEs have been cleared and a TLB flush is needed before releasing the 704faaf05b0SBen Gardon * MMU lock. 705faaf05b0SBen Gardon */ 7062b9663d8SSean Christopherson bool __kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, int as_id, gfn_t start, 7072b9663d8SSean Christopherson gfn_t end, bool can_yield, bool flush) 708faaf05b0SBen Gardon { 709faaf05b0SBen Gardon struct kvm_mmu_page *root; 710faaf05b0SBen Gardon 711a3f15bdaSSean Christopherson for_each_tdp_mmu_root_yield_safe(kvm, root, as_id) 71233a31641SSean Christopherson flush = zap_gfn_range(kvm, root, start, end, can_yield, flush); 713faaf05b0SBen Gardon 714faaf05b0SBen Gardon return flush; 715faaf05b0SBen Gardon } 716faaf05b0SBen Gardon 717faaf05b0SBen Gardon void kvm_tdp_mmu_zap_all(struct kvm *kvm) 718faaf05b0SBen Gardon { 719339f5a7fSRick Edgecombe gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT); 7202b9663d8SSean Christopherson bool flush = false; 7212b9663d8SSean Christopherson int i; 722faaf05b0SBen Gardon 7232b9663d8SSean Christopherson for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) 7242b9663d8SSean Christopherson flush = kvm_tdp_mmu_zap_gfn_range(kvm, i, 0, max_gfn, flush); 7252b9663d8SSean Christopherson 726faaf05b0SBen Gardon if (flush) 727faaf05b0SBen Gardon kvm_flush_remote_tlbs(kvm); 728faaf05b0SBen Gardon } 729bb18842eSBen Gardon 730bb18842eSBen Gardon /* 731bb18842eSBen Gardon * Installs a last-level SPTE to handle a TDP page fault. 732bb18842eSBen Gardon * (NPT/EPT violation/misconfiguration) 733bb18842eSBen Gardon */ 734bb18842eSBen Gardon static int tdp_mmu_map_handle_target_level(struct kvm_vcpu *vcpu, int write, 735bb18842eSBen Gardon int map_writable, 736bb18842eSBen Gardon struct tdp_iter *iter, 737bb18842eSBen Gardon kvm_pfn_t pfn, bool prefault) 738bb18842eSBen Gardon { 739bb18842eSBen Gardon u64 new_spte; 740bb18842eSBen Gardon int ret = 0; 741bb18842eSBen Gardon int make_spte_ret = 0; 742bb18842eSBen Gardon 7439a77daacSBen Gardon if (unlikely(is_noslot_pfn(pfn))) 744bb18842eSBen Gardon new_spte = make_mmio_spte(vcpu, iter->gfn, ACC_ALL); 7459a77daacSBen Gardon else 746bb18842eSBen Gardon make_spte_ret = make_spte(vcpu, ACC_ALL, iter->level, iter->gfn, 747bb18842eSBen Gardon pfn, iter->old_spte, prefault, true, 748bb18842eSBen Gardon map_writable, !shadow_accessed_mask, 749bb18842eSBen Gardon &new_spte); 750bb18842eSBen Gardon 751bb18842eSBen Gardon if (new_spte == iter->old_spte) 752bb18842eSBen Gardon ret = RET_PF_SPURIOUS; 7539a77daacSBen Gardon else if (!tdp_mmu_set_spte_atomic(vcpu->kvm, iter, new_spte)) 7549a77daacSBen Gardon return RET_PF_RETRY; 755bb18842eSBen Gardon 756bb18842eSBen Gardon /* 757bb18842eSBen Gardon * If the page fault was caused by a write but the page is write 758bb18842eSBen Gardon * protected, emulation is needed. If the emulation was skipped, 759bb18842eSBen Gardon * the vCPU would have the same fault again. 760bb18842eSBen Gardon */ 761bb18842eSBen Gardon if (make_spte_ret & SET_SPTE_WRITE_PROTECTED_PT) { 762bb18842eSBen Gardon if (write) 763bb18842eSBen Gardon ret = RET_PF_EMULATE; 764bb18842eSBen Gardon kvm_make_request(KVM_REQ_TLB_FLUSH_CURRENT, vcpu); 765bb18842eSBen Gardon } 766bb18842eSBen Gardon 767bb18842eSBen Gardon /* If a MMIO SPTE is installed, the MMIO will need to be emulated. */ 7689a77daacSBen Gardon if (unlikely(is_mmio_spte(new_spte))) { 7699a77daacSBen Gardon trace_mark_mmio_spte(rcu_dereference(iter->sptep), iter->gfn, 7709a77daacSBen Gardon new_spte); 771bb18842eSBen Gardon ret = RET_PF_EMULATE; 7723849e092SSean Christopherson } else { 7739a77daacSBen Gardon trace_kvm_mmu_set_spte(iter->level, iter->gfn, 7749a77daacSBen Gardon rcu_dereference(iter->sptep)); 7753849e092SSean Christopherson } 776bb18842eSBen Gardon 777bb18842eSBen Gardon if (!prefault) 778bb18842eSBen Gardon vcpu->stat.pf_fixed++; 779bb18842eSBen Gardon 780bb18842eSBen Gardon return ret; 781bb18842eSBen Gardon } 782bb18842eSBen Gardon 783bb18842eSBen Gardon /* 784bb18842eSBen Gardon * Handle a TDP page fault (NPT/EPT violation/misconfiguration) by installing 785bb18842eSBen Gardon * page tables and SPTEs to translate the faulting guest physical address. 786bb18842eSBen Gardon */ 787bb18842eSBen Gardon int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, 788bb18842eSBen Gardon int map_writable, int max_level, kvm_pfn_t pfn, 789bb18842eSBen Gardon bool prefault) 790bb18842eSBen Gardon { 791bb18842eSBen Gardon bool nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(); 792bb18842eSBen Gardon bool write = error_code & PFERR_WRITE_MASK; 793bb18842eSBen Gardon bool exec = error_code & PFERR_FETCH_MASK; 794bb18842eSBen Gardon bool huge_page_disallowed = exec && nx_huge_page_workaround_enabled; 795bb18842eSBen Gardon struct kvm_mmu *mmu = vcpu->arch.mmu; 796bb18842eSBen Gardon struct tdp_iter iter; 79789c0fd49SBen Gardon struct kvm_mmu_page *sp; 798bb18842eSBen Gardon u64 *child_pt; 799bb18842eSBen Gardon u64 new_spte; 800bb18842eSBen Gardon int ret; 801bb18842eSBen Gardon gfn_t gfn = gpa >> PAGE_SHIFT; 802bb18842eSBen Gardon int level; 803bb18842eSBen Gardon int req_level; 804bb18842eSBen Gardon 805bb18842eSBen Gardon if (WARN_ON(!VALID_PAGE(vcpu->arch.mmu->root_hpa))) 806bb18842eSBen Gardon return RET_PF_RETRY; 807bb18842eSBen Gardon if (WARN_ON(!is_tdp_mmu_root(vcpu->kvm, vcpu->arch.mmu->root_hpa))) 808bb18842eSBen Gardon return RET_PF_RETRY; 809bb18842eSBen Gardon 810bb18842eSBen Gardon level = kvm_mmu_hugepage_adjust(vcpu, gfn, max_level, &pfn, 811bb18842eSBen Gardon huge_page_disallowed, &req_level); 812bb18842eSBen Gardon 813bb18842eSBen Gardon trace_kvm_mmu_spte_requested(gpa, level, pfn); 8147cca2d0bSBen Gardon 8157cca2d0bSBen Gardon rcu_read_lock(); 8167cca2d0bSBen Gardon 817bb18842eSBen Gardon tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) { 818bb18842eSBen Gardon if (nx_huge_page_workaround_enabled) 819bb18842eSBen Gardon disallowed_hugepage_adjust(iter.old_spte, gfn, 820bb18842eSBen Gardon iter.level, &pfn, &level); 821bb18842eSBen Gardon 822bb18842eSBen Gardon if (iter.level == level) 823bb18842eSBen Gardon break; 824bb18842eSBen Gardon 825bb18842eSBen Gardon /* 826bb18842eSBen Gardon * If there is an SPTE mapping a large page at a higher level 827bb18842eSBen Gardon * than the target, that SPTE must be cleared and replaced 828bb18842eSBen Gardon * with a non-leaf SPTE. 829bb18842eSBen Gardon */ 830bb18842eSBen Gardon if (is_shadow_present_pte(iter.old_spte) && 831bb18842eSBen Gardon is_large_pte(iter.old_spte)) { 83208f07c80SBen Gardon if (!tdp_mmu_zap_spte_atomic(vcpu->kvm, &iter)) 8339a77daacSBen Gardon break; 834bb18842eSBen Gardon 835bb18842eSBen Gardon /* 836bb18842eSBen Gardon * The iter must explicitly re-read the spte here 837bb18842eSBen Gardon * because the new value informs the !present 838bb18842eSBen Gardon * path below. 839bb18842eSBen Gardon */ 8407cca2d0bSBen Gardon iter.old_spte = READ_ONCE(*rcu_dereference(iter.sptep)); 841bb18842eSBen Gardon } 842bb18842eSBen Gardon 843bb18842eSBen Gardon if (!is_shadow_present_pte(iter.old_spte)) { 84489c0fd49SBen Gardon sp = alloc_tdp_mmu_page(vcpu, iter.gfn, iter.level); 84589c0fd49SBen Gardon child_pt = sp->spt; 846a9442f59SBen Gardon 847bb18842eSBen Gardon new_spte = make_nonleaf_spte(child_pt, 848bb18842eSBen Gardon !shadow_accessed_mask); 849bb18842eSBen Gardon 8509a77daacSBen Gardon if (tdp_mmu_set_spte_atomic(vcpu->kvm, &iter, 8519a77daacSBen Gardon new_spte)) { 8529a77daacSBen Gardon tdp_mmu_link_page(vcpu->kvm, sp, true, 8539a77daacSBen Gardon huge_page_disallowed && 8549a77daacSBen Gardon req_level >= iter.level); 8559a77daacSBen Gardon 856bb18842eSBen Gardon trace_kvm_mmu_get_page(sp, true); 8579a77daacSBen Gardon } else { 8589a77daacSBen Gardon tdp_mmu_free_sp(sp); 8599a77daacSBen Gardon break; 8609a77daacSBen Gardon } 861bb18842eSBen Gardon } 862bb18842eSBen Gardon } 863bb18842eSBen Gardon 8649a77daacSBen Gardon if (iter.level != level) { 8657cca2d0bSBen Gardon rcu_read_unlock(); 866bb18842eSBen Gardon return RET_PF_RETRY; 8677cca2d0bSBen Gardon } 868bb18842eSBen Gardon 869bb18842eSBen Gardon ret = tdp_mmu_map_handle_target_level(vcpu, write, map_writable, &iter, 870bb18842eSBen Gardon pfn, prefault); 8717cca2d0bSBen Gardon rcu_read_unlock(); 872bb18842eSBen Gardon 873bb18842eSBen Gardon return ret; 874bb18842eSBen Gardon } 875063afacdSBen Gardon 8763039bcc7SSean Christopherson bool kvm_tdp_mmu_unmap_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range, 8773039bcc7SSean Christopherson bool flush) 8783039bcc7SSean Christopherson { 8793039bcc7SSean Christopherson struct kvm_mmu_page *root; 880c1b91493SSean Christopherson 8813039bcc7SSean Christopherson for_each_tdp_mmu_root(kvm, root, range->slot->as_id) 8823039bcc7SSean Christopherson flush |= zap_gfn_range(kvm, root, range->start, range->end, 883*e1eed584SSean Christopherson range->may_block, flush); 8843039bcc7SSean Christopherson 8853039bcc7SSean Christopherson return flush; 8863039bcc7SSean Christopherson } 8873039bcc7SSean Christopherson 8883039bcc7SSean Christopherson typedef bool (*tdp_handler_t)(struct kvm *kvm, struct tdp_iter *iter, 8893039bcc7SSean Christopherson struct kvm_gfn_range *range); 8903039bcc7SSean Christopherson 8913039bcc7SSean Christopherson static __always_inline bool kvm_tdp_mmu_handle_gfn(struct kvm *kvm, 8923039bcc7SSean Christopherson struct kvm_gfn_range *range, 893c1b91493SSean Christopherson tdp_handler_t handler) 894063afacdSBen Gardon { 895063afacdSBen Gardon struct kvm_mmu_page *root; 8963039bcc7SSean Christopherson struct tdp_iter iter; 8973039bcc7SSean Christopherson bool ret = false; 898063afacdSBen Gardon 8993039bcc7SSean Christopherson rcu_read_lock(); 900063afacdSBen Gardon 901*e1eed584SSean Christopherson /* 902*e1eed584SSean Christopherson * Don't support rescheduling, none of the MMU notifiers that funnel 903*e1eed584SSean Christopherson * into this helper allow blocking; it'd be dead, wasteful code. 904*e1eed584SSean Christopherson */ 9053039bcc7SSean Christopherson for_each_tdp_mmu_root(kvm, root, range->slot->as_id) { 9063039bcc7SSean Christopherson tdp_root_for_each_leaf_pte(iter, root, range->start, range->end) 9073039bcc7SSean Christopherson ret |= handler(kvm, &iter, range); 9083039bcc7SSean Christopherson } 909063afacdSBen Gardon 9103039bcc7SSean Christopherson rcu_read_unlock(); 911063afacdSBen Gardon 912063afacdSBen Gardon return ret; 913063afacdSBen Gardon } 914063afacdSBen Gardon 915f8e14497SBen Gardon /* 916f8e14497SBen Gardon * Mark the SPTEs range of GFNs [start, end) unaccessed and return non-zero 917f8e14497SBen Gardon * if any of the GFNs in the range have been accessed. 918f8e14497SBen Gardon */ 9193039bcc7SSean Christopherson static bool age_gfn_range(struct kvm *kvm, struct tdp_iter *iter, 9203039bcc7SSean Christopherson struct kvm_gfn_range *range) 921f8e14497SBen Gardon { 9223039bcc7SSean Christopherson u64 new_spte = 0; 923f8e14497SBen Gardon 9243039bcc7SSean Christopherson /* If we have a non-accessed entry we don't need to change the pte. */ 9253039bcc7SSean Christopherson if (!is_accessed_spte(iter->old_spte)) 9263039bcc7SSean Christopherson return false; 9277cca2d0bSBen Gardon 9283039bcc7SSean Christopherson new_spte = iter->old_spte; 929f8e14497SBen Gardon 930f8e14497SBen Gardon if (spte_ad_enabled(new_spte)) { 9318f8f52a4SSean Christopherson new_spte &= ~shadow_accessed_mask; 932f8e14497SBen Gardon } else { 933f8e14497SBen Gardon /* 934f8e14497SBen Gardon * Capture the dirty status of the page, so that it doesn't get 935f8e14497SBen Gardon * lost when the SPTE is marked for access tracking. 936f8e14497SBen Gardon */ 937f8e14497SBen Gardon if (is_writable_pte(new_spte)) 938f8e14497SBen Gardon kvm_set_pfn_dirty(spte_to_pfn(new_spte)); 939f8e14497SBen Gardon 940f8e14497SBen Gardon new_spte = mark_spte_for_access_track(new_spte); 941f8e14497SBen Gardon } 942f8e14497SBen Gardon 9433039bcc7SSean Christopherson tdp_mmu_set_spte_no_acc_track(kvm, iter, new_spte); 9443039bcc7SSean Christopherson 9453039bcc7SSean Christopherson return true; 946f8e14497SBen Gardon } 947f8e14497SBen Gardon 9483039bcc7SSean Christopherson bool kvm_tdp_mmu_age_gfn_range(struct kvm *kvm, struct kvm_gfn_range *range) 949f8e14497SBen Gardon { 9503039bcc7SSean Christopherson return kvm_tdp_mmu_handle_gfn(kvm, range, age_gfn_range); 951f8e14497SBen Gardon } 952f8e14497SBen Gardon 9533039bcc7SSean Christopherson static bool test_age_gfn(struct kvm *kvm, struct tdp_iter *iter, 9543039bcc7SSean Christopherson struct kvm_gfn_range *range) 955f8e14497SBen Gardon { 9563039bcc7SSean Christopherson return is_accessed_spte(iter->old_spte); 957f8e14497SBen Gardon } 958f8e14497SBen Gardon 9593039bcc7SSean Christopherson bool kvm_tdp_mmu_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 960f8e14497SBen Gardon { 9613039bcc7SSean Christopherson return kvm_tdp_mmu_handle_gfn(kvm, range, test_age_gfn); 9623039bcc7SSean Christopherson } 9633039bcc7SSean Christopherson 9643039bcc7SSean Christopherson static bool set_spte_gfn(struct kvm *kvm, struct tdp_iter *iter, 9653039bcc7SSean Christopherson struct kvm_gfn_range *range) 9663039bcc7SSean Christopherson { 9673039bcc7SSean Christopherson u64 new_spte; 9683039bcc7SSean Christopherson 9693039bcc7SSean Christopherson /* Huge pages aren't expected to be modified without first being zapped. */ 9703039bcc7SSean Christopherson WARN_ON(pte_huge(range->pte) || range->start + 1 != range->end); 9713039bcc7SSean Christopherson 9723039bcc7SSean Christopherson if (iter->level != PG_LEVEL_4K || 9733039bcc7SSean Christopherson !is_shadow_present_pte(iter->old_spte)) 9743039bcc7SSean Christopherson return false; 9753039bcc7SSean Christopherson 9763039bcc7SSean Christopherson /* 9773039bcc7SSean Christopherson * Note, when changing a read-only SPTE, it's not strictly necessary to 9783039bcc7SSean Christopherson * zero the SPTE before setting the new PFN, but doing so preserves the 9793039bcc7SSean Christopherson * invariant that the PFN of a present * leaf SPTE can never change. 9803039bcc7SSean Christopherson * See __handle_changed_spte(). 9813039bcc7SSean Christopherson */ 9823039bcc7SSean Christopherson tdp_mmu_set_spte(kvm, iter, 0); 9833039bcc7SSean Christopherson 9843039bcc7SSean Christopherson if (!pte_write(range->pte)) { 9853039bcc7SSean Christopherson new_spte = kvm_mmu_changed_pte_notifier_make_spte(iter->old_spte, 9863039bcc7SSean Christopherson pte_pfn(range->pte)); 9873039bcc7SSean Christopherson 9883039bcc7SSean Christopherson tdp_mmu_set_spte(kvm, iter, new_spte); 9893039bcc7SSean Christopherson } 9903039bcc7SSean Christopherson 9913039bcc7SSean Christopherson return true; 992f8e14497SBen Gardon } 9931d8dd6b3SBen Gardon 9941d8dd6b3SBen Gardon /* 9951d8dd6b3SBen Gardon * Handle the changed_pte MMU notifier for the TDP MMU. 9961d8dd6b3SBen Gardon * data is a pointer to the new pte_t mapping the HVA specified by the MMU 9971d8dd6b3SBen Gardon * notifier. 9981d8dd6b3SBen Gardon * Returns non-zero if a flush is needed before releasing the MMU lock. 9991d8dd6b3SBen Gardon */ 10003039bcc7SSean Christopherson bool kvm_tdp_mmu_set_spte_gfn(struct kvm *kvm, struct kvm_gfn_range *range) 10011d8dd6b3SBen Gardon { 10023039bcc7SSean Christopherson bool flush = kvm_tdp_mmu_handle_gfn(kvm, range, set_spte_gfn); 10031d8dd6b3SBen Gardon 10043039bcc7SSean Christopherson /* FIXME: return 'flush' instead of flushing here. */ 10053039bcc7SSean Christopherson if (flush) 10063039bcc7SSean Christopherson kvm_flush_remote_tlbs_with_address(kvm, range->start, 1); 10077cca2d0bSBen Gardon 10083039bcc7SSean Christopherson return false; 10091d8dd6b3SBen Gardon } 10101d8dd6b3SBen Gardon 1011a6a0b05dSBen Gardon /* 1012a6a0b05dSBen Gardon * Remove write access from all the SPTEs mapping GFNs [start, end). If 1013a6a0b05dSBen Gardon * skip_4k is set, SPTEs that map 4k pages, will not be write-protected. 1014a6a0b05dSBen Gardon * Returns true if an SPTE has been changed and the TLBs need to be flushed. 1015a6a0b05dSBen Gardon */ 1016a6a0b05dSBen Gardon static bool wrprot_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, 1017a6a0b05dSBen Gardon gfn_t start, gfn_t end, int min_level) 1018a6a0b05dSBen Gardon { 1019a6a0b05dSBen Gardon struct tdp_iter iter; 1020a6a0b05dSBen Gardon u64 new_spte; 1021a6a0b05dSBen Gardon bool spte_set = false; 1022a6a0b05dSBen Gardon 10237cca2d0bSBen Gardon rcu_read_lock(); 10247cca2d0bSBen Gardon 1025a6a0b05dSBen Gardon BUG_ON(min_level > KVM_MAX_HUGEPAGE_LEVEL); 1026a6a0b05dSBen Gardon 1027a6a0b05dSBen Gardon for_each_tdp_pte_min_level(iter, root->spt, root->role.level, 1028a6a0b05dSBen Gardon min_level, start, end) { 10291af4a960SBen Gardon if (tdp_mmu_iter_cond_resched(kvm, &iter, false)) 10301af4a960SBen Gardon continue; 10311af4a960SBen Gardon 1032a6a0b05dSBen Gardon if (!is_shadow_present_pte(iter.old_spte) || 10330f99ee2cSBen Gardon !is_last_spte(iter.old_spte, iter.level) || 10340f99ee2cSBen Gardon !(iter.old_spte & PT_WRITABLE_MASK)) 1035a6a0b05dSBen Gardon continue; 1036a6a0b05dSBen Gardon 1037a6a0b05dSBen Gardon new_spte = iter.old_spte & ~PT_WRITABLE_MASK; 1038a6a0b05dSBen Gardon 1039a6a0b05dSBen Gardon tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte); 1040a6a0b05dSBen Gardon spte_set = true; 1041a6a0b05dSBen Gardon } 10427cca2d0bSBen Gardon 10437cca2d0bSBen Gardon rcu_read_unlock(); 1044a6a0b05dSBen Gardon return spte_set; 1045a6a0b05dSBen Gardon } 1046a6a0b05dSBen Gardon 1047a6a0b05dSBen Gardon /* 1048a6a0b05dSBen Gardon * Remove write access from all the SPTEs mapping GFNs in the memslot. Will 1049a6a0b05dSBen Gardon * only affect leaf SPTEs down to min_level. 1050a6a0b05dSBen Gardon * Returns true if an SPTE has been changed and the TLBs need to be flushed. 1051a6a0b05dSBen Gardon */ 1052a6a0b05dSBen Gardon bool kvm_tdp_mmu_wrprot_slot(struct kvm *kvm, struct kvm_memory_slot *slot, 1053a6a0b05dSBen Gardon int min_level) 1054a6a0b05dSBen Gardon { 1055a6a0b05dSBen Gardon struct kvm_mmu_page *root; 1056a6a0b05dSBen Gardon bool spte_set = false; 1057a6a0b05dSBen Gardon 1058a3f15bdaSSean Christopherson for_each_tdp_mmu_root_yield_safe(kvm, root, slot->as_id) 1059a6a0b05dSBen Gardon spte_set |= wrprot_gfn_range(kvm, root, slot->base_gfn, 1060a6a0b05dSBen Gardon slot->base_gfn + slot->npages, min_level); 1061a6a0b05dSBen Gardon 1062a6a0b05dSBen Gardon return spte_set; 1063a6a0b05dSBen Gardon } 1064a6a0b05dSBen Gardon 1065a6a0b05dSBen Gardon /* 1066a6a0b05dSBen Gardon * Clear the dirty status of all the SPTEs mapping GFNs in the memslot. If 1067a6a0b05dSBen Gardon * AD bits are enabled, this will involve clearing the dirty bit on each SPTE. 1068a6a0b05dSBen Gardon * If AD bits are not enabled, this will require clearing the writable bit on 1069a6a0b05dSBen Gardon * each SPTE. Returns true if an SPTE has been changed and the TLBs need to 1070a6a0b05dSBen Gardon * be flushed. 1071a6a0b05dSBen Gardon */ 1072a6a0b05dSBen Gardon static bool clear_dirty_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, 1073a6a0b05dSBen Gardon gfn_t start, gfn_t end) 1074a6a0b05dSBen Gardon { 1075a6a0b05dSBen Gardon struct tdp_iter iter; 1076a6a0b05dSBen Gardon u64 new_spte; 1077a6a0b05dSBen Gardon bool spte_set = false; 1078a6a0b05dSBen Gardon 10797cca2d0bSBen Gardon rcu_read_lock(); 10807cca2d0bSBen Gardon 1081a6a0b05dSBen Gardon tdp_root_for_each_leaf_pte(iter, root, start, end) { 10821af4a960SBen Gardon if (tdp_mmu_iter_cond_resched(kvm, &iter, false)) 10831af4a960SBen Gardon continue; 10841af4a960SBen Gardon 1085a6a0b05dSBen Gardon if (spte_ad_need_write_protect(iter.old_spte)) { 1086a6a0b05dSBen Gardon if (is_writable_pte(iter.old_spte)) 1087a6a0b05dSBen Gardon new_spte = iter.old_spte & ~PT_WRITABLE_MASK; 1088a6a0b05dSBen Gardon else 1089a6a0b05dSBen Gardon continue; 1090a6a0b05dSBen Gardon } else { 1091a6a0b05dSBen Gardon if (iter.old_spte & shadow_dirty_mask) 1092a6a0b05dSBen Gardon new_spte = iter.old_spte & ~shadow_dirty_mask; 1093a6a0b05dSBen Gardon else 1094a6a0b05dSBen Gardon continue; 1095a6a0b05dSBen Gardon } 1096a6a0b05dSBen Gardon 1097a6a0b05dSBen Gardon tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte); 1098a6a0b05dSBen Gardon spte_set = true; 1099a6a0b05dSBen Gardon } 11007cca2d0bSBen Gardon 11017cca2d0bSBen Gardon rcu_read_unlock(); 1102a6a0b05dSBen Gardon return spte_set; 1103a6a0b05dSBen Gardon } 1104a6a0b05dSBen Gardon 1105a6a0b05dSBen Gardon /* 1106a6a0b05dSBen Gardon * Clear the dirty status of all the SPTEs mapping GFNs in the memslot. If 1107a6a0b05dSBen Gardon * AD bits are enabled, this will involve clearing the dirty bit on each SPTE. 1108a6a0b05dSBen Gardon * If AD bits are not enabled, this will require clearing the writable bit on 1109a6a0b05dSBen Gardon * each SPTE. Returns true if an SPTE has been changed and the TLBs need to 1110a6a0b05dSBen Gardon * be flushed. 1111a6a0b05dSBen Gardon */ 1112a6a0b05dSBen Gardon bool kvm_tdp_mmu_clear_dirty_slot(struct kvm *kvm, struct kvm_memory_slot *slot) 1113a6a0b05dSBen Gardon { 1114a6a0b05dSBen Gardon struct kvm_mmu_page *root; 1115a6a0b05dSBen Gardon bool spte_set = false; 1116a6a0b05dSBen Gardon 1117a3f15bdaSSean Christopherson for_each_tdp_mmu_root_yield_safe(kvm, root, slot->as_id) 1118a6a0b05dSBen Gardon spte_set |= clear_dirty_gfn_range(kvm, root, slot->base_gfn, 1119a6a0b05dSBen Gardon slot->base_gfn + slot->npages); 1120a6a0b05dSBen Gardon 1121a6a0b05dSBen Gardon return spte_set; 1122a6a0b05dSBen Gardon } 1123a6a0b05dSBen Gardon 1124a6a0b05dSBen Gardon /* 1125a6a0b05dSBen Gardon * Clears the dirty status of all the 4k SPTEs mapping GFNs for which a bit is 1126a6a0b05dSBen Gardon * set in mask, starting at gfn. The given memslot is expected to contain all 1127a6a0b05dSBen Gardon * the GFNs represented by set bits in the mask. If AD bits are enabled, 1128a6a0b05dSBen Gardon * clearing the dirty status will involve clearing the dirty bit on each SPTE 1129a6a0b05dSBen Gardon * or, if AD bits are not enabled, clearing the writable bit on each SPTE. 1130a6a0b05dSBen Gardon */ 1131a6a0b05dSBen Gardon static void clear_dirty_pt_masked(struct kvm *kvm, struct kvm_mmu_page *root, 1132a6a0b05dSBen Gardon gfn_t gfn, unsigned long mask, bool wrprot) 1133a6a0b05dSBen Gardon { 1134a6a0b05dSBen Gardon struct tdp_iter iter; 1135a6a0b05dSBen Gardon u64 new_spte; 1136a6a0b05dSBen Gardon 11377cca2d0bSBen Gardon rcu_read_lock(); 11387cca2d0bSBen Gardon 1139a6a0b05dSBen Gardon tdp_root_for_each_leaf_pte(iter, root, gfn + __ffs(mask), 1140a6a0b05dSBen Gardon gfn + BITS_PER_LONG) { 1141a6a0b05dSBen Gardon if (!mask) 1142a6a0b05dSBen Gardon break; 1143a6a0b05dSBen Gardon 1144a6a0b05dSBen Gardon if (iter.level > PG_LEVEL_4K || 1145a6a0b05dSBen Gardon !(mask & (1UL << (iter.gfn - gfn)))) 1146a6a0b05dSBen Gardon continue; 1147a6a0b05dSBen Gardon 1148f1b3b06aSBen Gardon mask &= ~(1UL << (iter.gfn - gfn)); 1149f1b3b06aSBen Gardon 1150a6a0b05dSBen Gardon if (wrprot || spte_ad_need_write_protect(iter.old_spte)) { 1151a6a0b05dSBen Gardon if (is_writable_pte(iter.old_spte)) 1152a6a0b05dSBen Gardon new_spte = iter.old_spte & ~PT_WRITABLE_MASK; 1153a6a0b05dSBen Gardon else 1154a6a0b05dSBen Gardon continue; 1155a6a0b05dSBen Gardon } else { 1156a6a0b05dSBen Gardon if (iter.old_spte & shadow_dirty_mask) 1157a6a0b05dSBen Gardon new_spte = iter.old_spte & ~shadow_dirty_mask; 1158a6a0b05dSBen Gardon else 1159a6a0b05dSBen Gardon continue; 1160a6a0b05dSBen Gardon } 1161a6a0b05dSBen Gardon 1162a6a0b05dSBen Gardon tdp_mmu_set_spte_no_dirty_log(kvm, &iter, new_spte); 1163a6a0b05dSBen Gardon } 11647cca2d0bSBen Gardon 11657cca2d0bSBen Gardon rcu_read_unlock(); 1166a6a0b05dSBen Gardon } 1167a6a0b05dSBen Gardon 1168a6a0b05dSBen Gardon /* 1169a6a0b05dSBen Gardon * Clears the dirty status of all the 4k SPTEs mapping GFNs for which a bit is 1170a6a0b05dSBen Gardon * set in mask, starting at gfn. The given memslot is expected to contain all 1171a6a0b05dSBen Gardon * the GFNs represented by set bits in the mask. If AD bits are enabled, 1172a6a0b05dSBen Gardon * clearing the dirty status will involve clearing the dirty bit on each SPTE 1173a6a0b05dSBen Gardon * or, if AD bits are not enabled, clearing the writable bit on each SPTE. 1174a6a0b05dSBen Gardon */ 1175a6a0b05dSBen Gardon void kvm_tdp_mmu_clear_dirty_pt_masked(struct kvm *kvm, 1176a6a0b05dSBen Gardon struct kvm_memory_slot *slot, 1177a6a0b05dSBen Gardon gfn_t gfn, unsigned long mask, 1178a6a0b05dSBen Gardon bool wrprot) 1179a6a0b05dSBen Gardon { 1180a6a0b05dSBen Gardon struct kvm_mmu_page *root; 1181a6a0b05dSBen Gardon 1182531810caSBen Gardon lockdep_assert_held_write(&kvm->mmu_lock); 1183a3f15bdaSSean Christopherson for_each_tdp_mmu_root(kvm, root, slot->as_id) 1184a6a0b05dSBen Gardon clear_dirty_pt_masked(kvm, root, gfn, mask, wrprot); 1185a6a0b05dSBen Gardon } 1186a6a0b05dSBen Gardon 1187a6a0b05dSBen Gardon /* 118887aa9ec9SBen Gardon * Clear leaf entries which could be replaced by large mappings, for 118987aa9ec9SBen Gardon * GFNs within the slot. 119014881998SBen Gardon */ 1191af95b53eSSean Christopherson static bool zap_collapsible_spte_range(struct kvm *kvm, 119214881998SBen Gardon struct kvm_mmu_page *root, 1193af95b53eSSean Christopherson struct kvm_memory_slot *slot, 1194af95b53eSSean Christopherson bool flush) 119514881998SBen Gardon { 11969eba50f8SSean Christopherson gfn_t start = slot->base_gfn; 11979eba50f8SSean Christopherson gfn_t end = start + slot->npages; 119814881998SBen Gardon struct tdp_iter iter; 119914881998SBen Gardon kvm_pfn_t pfn; 120014881998SBen Gardon 12017cca2d0bSBen Gardon rcu_read_lock(); 12027cca2d0bSBen Gardon 120314881998SBen Gardon tdp_root_for_each_pte(iter, root, start, end) { 1204af95b53eSSean Christopherson if (tdp_mmu_iter_cond_resched(kvm, &iter, flush)) { 1205af95b53eSSean Christopherson flush = false; 12061af4a960SBen Gardon continue; 12071af4a960SBen Gardon } 12081af4a960SBen Gardon 120914881998SBen Gardon if (!is_shadow_present_pte(iter.old_spte) || 121087aa9ec9SBen Gardon !is_last_spte(iter.old_spte, iter.level)) 121114881998SBen Gardon continue; 121214881998SBen Gardon 121314881998SBen Gardon pfn = spte_to_pfn(iter.old_spte); 121414881998SBen Gardon if (kvm_is_reserved_pfn(pfn) || 12159eba50f8SSean Christopherson iter.level >= kvm_mmu_max_mapping_level(kvm, slot, iter.gfn, 12169eba50f8SSean Christopherson pfn, PG_LEVEL_NUM)) 121714881998SBen Gardon continue; 121814881998SBen Gardon 121914881998SBen Gardon tdp_mmu_set_spte(kvm, &iter, 0); 122014881998SBen Gardon 1221af95b53eSSean Christopherson flush = true; 122214881998SBen Gardon } 122314881998SBen Gardon 12247cca2d0bSBen Gardon rcu_read_unlock(); 1225af95b53eSSean Christopherson 1226af95b53eSSean Christopherson return flush; 122714881998SBen Gardon } 122814881998SBen Gardon 122914881998SBen Gardon /* 123014881998SBen Gardon * Clear non-leaf entries (and free associated page tables) which could 123114881998SBen Gardon * be replaced by large mappings, for GFNs within the slot. 123214881998SBen Gardon */ 1233142ccde1SSean Christopherson bool kvm_tdp_mmu_zap_collapsible_sptes(struct kvm *kvm, 1234142ccde1SSean Christopherson struct kvm_memory_slot *slot, bool flush) 123514881998SBen Gardon { 123614881998SBen Gardon struct kvm_mmu_page *root; 123714881998SBen Gardon 1238a3f15bdaSSean Christopherson for_each_tdp_mmu_root_yield_safe(kvm, root, slot->as_id) 1239af95b53eSSean Christopherson flush = zap_collapsible_spte_range(kvm, root, slot, flush); 1240af95b53eSSean Christopherson 1241142ccde1SSean Christopherson return flush; 124214881998SBen Gardon } 124346044f72SBen Gardon 124446044f72SBen Gardon /* 124546044f72SBen Gardon * Removes write access on the last level SPTE mapping this GFN and unsets the 12465fc3424fSSean Christopherson * MMU-writable bit to ensure future writes continue to be intercepted. 124746044f72SBen Gardon * Returns true if an SPTE was set and a TLB flush is needed. 124846044f72SBen Gardon */ 124946044f72SBen Gardon static bool write_protect_gfn(struct kvm *kvm, struct kvm_mmu_page *root, 125046044f72SBen Gardon gfn_t gfn) 125146044f72SBen Gardon { 125246044f72SBen Gardon struct tdp_iter iter; 125346044f72SBen Gardon u64 new_spte; 125446044f72SBen Gardon bool spte_set = false; 125546044f72SBen Gardon 12567cca2d0bSBen Gardon rcu_read_lock(); 12577cca2d0bSBen Gardon 125846044f72SBen Gardon tdp_root_for_each_leaf_pte(iter, root, gfn, gfn + 1) { 125946044f72SBen Gardon if (!is_writable_pte(iter.old_spte)) 126046044f72SBen Gardon break; 126146044f72SBen Gardon 126246044f72SBen Gardon new_spte = iter.old_spte & 12635fc3424fSSean Christopherson ~(PT_WRITABLE_MASK | shadow_mmu_writable_mask); 126446044f72SBen Gardon 126546044f72SBen Gardon tdp_mmu_set_spte(kvm, &iter, new_spte); 126646044f72SBen Gardon spte_set = true; 126746044f72SBen Gardon } 126846044f72SBen Gardon 12697cca2d0bSBen Gardon rcu_read_unlock(); 12707cca2d0bSBen Gardon 127146044f72SBen Gardon return spte_set; 127246044f72SBen Gardon } 127346044f72SBen Gardon 127446044f72SBen Gardon /* 127546044f72SBen Gardon * Removes write access on the last level SPTE mapping this GFN and unsets the 12765fc3424fSSean Christopherson * MMU-writable bit to ensure future writes continue to be intercepted. 127746044f72SBen Gardon * Returns true if an SPTE was set and a TLB flush is needed. 127846044f72SBen Gardon */ 127946044f72SBen Gardon bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm, 128046044f72SBen Gardon struct kvm_memory_slot *slot, gfn_t gfn) 128146044f72SBen Gardon { 128246044f72SBen Gardon struct kvm_mmu_page *root; 128346044f72SBen Gardon bool spte_set = false; 128446044f72SBen Gardon 1285531810caSBen Gardon lockdep_assert_held_write(&kvm->mmu_lock); 1286a3f15bdaSSean Christopherson for_each_tdp_mmu_root(kvm, root, slot->as_id) 128746044f72SBen Gardon spte_set |= write_protect_gfn(kvm, root, gfn); 1288a3f15bdaSSean Christopherson 128946044f72SBen Gardon return spte_set; 129046044f72SBen Gardon } 129146044f72SBen Gardon 129295fb5b02SBen Gardon /* 129395fb5b02SBen Gardon * Return the level of the lowest level SPTE added to sptes. 129495fb5b02SBen Gardon * That SPTE may be non-present. 129595fb5b02SBen Gardon */ 129639b4d43eSSean Christopherson int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, 129739b4d43eSSean Christopherson int *root_level) 129895fb5b02SBen Gardon { 129995fb5b02SBen Gardon struct tdp_iter iter; 130095fb5b02SBen Gardon struct kvm_mmu *mmu = vcpu->arch.mmu; 130195fb5b02SBen Gardon gfn_t gfn = addr >> PAGE_SHIFT; 13022aa07893SSean Christopherson int leaf = -1; 130395fb5b02SBen Gardon 130439b4d43eSSean Christopherson *root_level = vcpu->arch.mmu->shadow_root_level; 130595fb5b02SBen Gardon 13067cca2d0bSBen Gardon rcu_read_lock(); 13077cca2d0bSBen Gardon 130895fb5b02SBen Gardon tdp_mmu_for_each_pte(iter, mmu, gfn, gfn + 1) { 130995fb5b02SBen Gardon leaf = iter.level; 1310dde81f94SSean Christopherson sptes[leaf] = iter.old_spte; 131195fb5b02SBen Gardon } 131295fb5b02SBen Gardon 13137cca2d0bSBen Gardon rcu_read_unlock(); 13147cca2d0bSBen Gardon 131595fb5b02SBen Gardon return leaf; 131695fb5b02SBen Gardon } 1317