/* SPDX-License-Identifier: GPL-2.0 */ #ifndef __KVM_X86_MMU_H #define __KVM_X86_MMU_H #include #include "kvm_cache_regs.h" #include "cpuid.h" #define PT64_PT_BITS 9 #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS) #define PT32_PT_BITS 10 #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS) #define PT_WRITABLE_SHIFT 1 #define PT_USER_SHIFT 2 #define PT_PRESENT_MASK (1ULL << 0) #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT) #define PT_USER_MASK (1ULL << PT_USER_SHIFT) #define PT_PWT_MASK (1ULL << 3) #define PT_PCD_MASK (1ULL << 4) #define PT_ACCESSED_SHIFT 5 #define PT_ACCESSED_MASK (1ULL << PT_ACCESSED_SHIFT) #define PT_DIRTY_SHIFT 6 #define PT_DIRTY_MASK (1ULL << PT_DIRTY_SHIFT) #define PT_PAGE_SIZE_SHIFT 7 #define PT_PAGE_SIZE_MASK (1ULL << PT_PAGE_SIZE_SHIFT) #define PT_PAT_MASK (1ULL << 7) #define PT_GLOBAL_MASK (1ULL << 8) #define PT64_NX_SHIFT 63 #define PT64_NX_MASK (1ULL << PT64_NX_SHIFT) #define PT_PAT_SHIFT 7 #define PT_DIR_PAT_SHIFT 12 #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT) #define PT32_DIR_PSE36_SIZE 4 #define PT32_DIR_PSE36_SHIFT 13 #define PT32_DIR_PSE36_MASK \ (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT) #define PT64_ROOT_5LEVEL 5 #define PT64_ROOT_4LEVEL 4 #define PT32_ROOT_LEVEL 2 #define PT32E_ROOT_LEVEL 3 #define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PSE | X86_CR4_PAE | X86_CR4_LA57 | \ X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE) #define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP) #define KVM_MMU_EFER_ROLE_BITS (EFER_LME | EFER_NX) static __always_inline u64 rsvd_bits(int s, int e) { BUILD_BUG_ON(__builtin_constant_p(e) && __builtin_constant_p(s) && e < s); if (__builtin_constant_p(e)) BUILD_BUG_ON(e > 63); else e &= 63; if (e < s) return 0; return ((2ULL << (e - s)) - 1) << s; } /* * The number of non-reserved physical address bits irrespective of features * that repurpose legal bits, e.g. MKTME. */ extern u8 __read_mostly shadow_phys_bits; static inline gfn_t kvm_mmu_max_gfn(void) { /* * Note that this uses the host MAXPHYADDR, not the guest's. * EPT/NPT cannot support GPAs that would exceed host.MAXPHYADDR; * assuming KVM is running on bare metal, guest accesses beyond * host.MAXPHYADDR will hit a #PF(RSVD) and never cause a vmexit * (either EPT Violation/Misconfig or #NPF), and so KVM will never * install a SPTE for such addresses. If KVM is running as a VM * itself, on the other hand, it might see a MAXPHYADDR that is less * than hardware's real MAXPHYADDR. Using the host MAXPHYADDR * disallows such SPTEs entirely and simplifies the TDP MMU. */ int max_gpa_bits = likely(tdp_enabled) ? shadow_phys_bits : 52; return (1ULL << (max_gpa_bits - PAGE_SHIFT)) - 1; } void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask); void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only); void kvm_init_mmu(struct kvm_vcpu *vcpu); void kvm_init_shadow_npt_mmu(struct kvm_vcpu *vcpu, unsigned long cr0, unsigned long cr4, u64 efer, gpa_t nested_cr3); void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, int huge_page_level, bool accessed_dirty, gpa_t new_eptp); bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu); int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, u64 fault_address, char *insn, int insn_len); int kvm_mmu_load(struct kvm_vcpu *vcpu); void kvm_mmu_unload(struct kvm_vcpu *vcpu); void kvm_mmu_free_obsolete_roots(struct kvm_vcpu *vcpu); void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu); void kvm_mmu_sync_prev_roots(struct kvm_vcpu *vcpu); static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu) { if (likely(vcpu->arch.mmu->root.hpa != INVALID_PAGE)) return 0; return kvm_mmu_load(vcpu); } static inline unsigned long kvm_get_pcid(struct kvm_vcpu *vcpu, gpa_t cr3) { BUILD_BUG_ON((X86_CR3_PCID_MASK & PAGE_MASK) != 0); return kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE) ? cr3 & X86_CR3_PCID_MASK : 0; } static inline unsigned long kvm_get_active_pcid(struct kvm_vcpu *vcpu) { return kvm_get_pcid(vcpu, kvm_read_cr3(vcpu)); } static inline void kvm_mmu_load_pgd(struct kvm_vcpu *vcpu) { u64 root_hpa = vcpu->arch.mmu->root.hpa; if (!VALID_PAGE(root_hpa)) return; static_call(kvm_x86_load_mmu_pgd)(vcpu, root_hpa, vcpu->arch.mmu->root_role.level); } struct kvm_page_fault { /* arguments to kvm_mmu_do_page_fault. */ const gpa_t addr; const u32 error_code; const bool prefetch; /* Derived from error_code. */ const bool exec; const bool write; const bool present; const bool rsvd; const bool user; /* Derived from mmu and global state. */ const bool is_tdp; const bool nx_huge_page_workaround_enabled; /* * Whether a >4KB mapping can be created or is forbidden due to NX * hugepages. */ bool huge_page_disallowed; /* * Maximum page size that can be created for this fault; input to * FNAME(fetch), __direct_map and kvm_tdp_mmu_map. */ u8 max_level; /* * Page size that can be created based on the max_level and the * page size used by the host mapping. */ u8 req_level; /* * Page size that will be created based on the req_level and * huge_page_disallowed. */ u8 goal_level; /* Shifted addr, or result of guest page table walk if addr is a gva. */ gfn_t gfn; /* The memslot containing gfn. May be NULL. */ struct kvm_memory_slot *slot; /* Outputs of kvm_faultin_pfn. */ kvm_pfn_t pfn; hva_t hva; bool map_writable; }; int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault); extern int nx_huge_pages; static inline bool is_nx_huge_page_enabled(void) { return READ_ONCE(nx_huge_pages); } static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u32 err, bool prefetch) { struct kvm_page_fault fault = { .addr = cr2_or_gpa, .error_code = err, .exec = err & PFERR_FETCH_MASK, .write = err & PFERR_WRITE_MASK, .present = err & PFERR_PRESENT_MASK, .rsvd = err & PFERR_RSVD_MASK, .user = err & PFERR_USER_MASK, .prefetch = prefetch, .is_tdp = likely(vcpu->arch.mmu->page_fault == kvm_tdp_page_fault), .nx_huge_page_workaround_enabled = is_nx_huge_page_enabled(), .max_level = KVM_MAX_HUGEPAGE_LEVEL, .req_level = PG_LEVEL_4K, .goal_level = PG_LEVEL_4K, }; #ifdef CONFIG_RETPOLINE if (fault.is_tdp) return kvm_tdp_page_fault(vcpu, &fault); #endif return vcpu->arch.mmu->page_fault(vcpu, &fault); } /* * Check if a given access (described through the I/D, W/R and U/S bits of a * page fault error code pfec) causes a permission fault with the given PTE * access rights (in ACC_* format). * * Return zero if the access does not fault; return the page fault error code * if the access faults. */ static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, unsigned pte_access, unsigned pte_pkey, u64 access) { /* strip nested paging fault error codes */ unsigned int pfec = access; unsigned long rflags = static_call(kvm_x86_get_rflags)(vcpu); /* * For explicit supervisor accesses, SMAP is disabled if EFLAGS.AC = 1. * For implicit supervisor accesses, SMAP cannot be overridden. * * SMAP works on supervisor accesses only, and not_smap can * be set or not set when user access with neither has any bearing * on the result. * * We put the SMAP checking bit in place of the PFERR_RSVD_MASK bit; * this bit will always be zero in pfec, but it will be one in index * if SMAP checks are being disabled. */ u64 implicit_access = access & PFERR_IMPLICIT_ACCESS; bool not_smap = ((rflags & X86_EFLAGS_AC) | implicit_access) == X86_EFLAGS_AC; int index = (pfec + (not_smap << PFERR_RSVD_BIT)) >> 1; bool fault = (mmu->permissions[index] >> pte_access) & 1; u32 errcode = PFERR_PRESENT_MASK; WARN_ON(pfec & (PFERR_PK_MASK | PFERR_RSVD_MASK)); if (unlikely(mmu->pkru_mask)) { u32 pkru_bits, offset; /* * PKRU defines 32 bits, there are 16 domains and 2 * attribute bits per domain in pkru. pte_pkey is the * index of the protection domain, so pte_pkey * 2 is * is the index of the first bit for the domain. */ pkru_bits = (vcpu->arch.pkru >> (pte_pkey * 2)) & 3; /* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */ offset = (pfec & ~1) + ((pte_access & PT_USER_MASK) << (PFERR_RSVD_BIT - PT_USER_SHIFT)); pkru_bits &= mmu->pkru_mask >> offset; errcode |= -pkru_bits & PFERR_PK_MASK; fault |= (pkru_bits != 0); } return -(u32)fault & errcode; } void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end); int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu); int kvm_mmu_post_init_vm(struct kvm *kvm); void kvm_mmu_pre_destroy_vm(struct kvm *kvm); static inline bool kvm_shadow_root_allocated(struct kvm *kvm) { /* * Read shadow_root_allocated before related pointers. Hence, threads * reading shadow_root_allocated in any lock context are guaranteed to * see the pointers. Pairs with smp_store_release in * mmu_first_shadow_root_alloc. */ return smp_load_acquire(&kvm->arch.shadow_root_allocated); } #ifdef CONFIG_X86_64 static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return kvm->arch.tdp_mmu_enabled; } #else static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return false; } #endif static inline bool kvm_memslots_have_rmaps(struct kvm *kvm) { return !is_tdp_mmu_enabled(kvm) || kvm_shadow_root_allocated(kvm); } static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level) { /* KVM_HPAGE_GFN_SHIFT(PG_LEVEL_4K) must be 0. */ return (gfn >> KVM_HPAGE_GFN_SHIFT(level)) - (base_gfn >> KVM_HPAGE_GFN_SHIFT(level)); } static inline unsigned long __kvm_mmu_slot_lpages(struct kvm_memory_slot *slot, unsigned long npages, int level) { return gfn_to_index(slot->base_gfn + npages - 1, slot->base_gfn, level) + 1; } static inline unsigned long kvm_mmu_slot_lpages(struct kvm_memory_slot *slot, int level) { return __kvm_mmu_slot_lpages(slot, slot->npages, level); } static inline void kvm_update_page_stats(struct kvm *kvm, int level, int count) { atomic64_add(count, &kvm->stat.pages[level - 1]); } gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u64 access, struct x86_exception *exception); static inline gpa_t kvm_translate_gpa(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, gpa_t gpa, u64 access, struct x86_exception *exception) { if (mmu != &vcpu->arch.nested_mmu) return gpa; return translate_nested_gpa(vcpu, gpa, access, exception); } #endif