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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1d737c8a ZX |
2 | #ifndef __KVM_X86_MMU_H |
3 | #define __KVM_X86_MMU_H | |
4 | ||
edf88417 | 5 | #include <linux/kvm_host.h> |
fc78f519 | 6 | #include "kvm_cache_regs.h" |
1d737c8a | 7 | |
8c6d6adc SY |
8 | #define PT64_PT_BITS 9 |
9 | #define PT64_ENT_PER_PAGE (1 << PT64_PT_BITS) | |
10 | #define PT32_PT_BITS 10 | |
11 | #define PT32_ENT_PER_PAGE (1 << PT32_PT_BITS) | |
12 | ||
13 | #define PT_WRITABLE_SHIFT 1 | |
be94f6b7 | 14 | #define PT_USER_SHIFT 2 |
8c6d6adc SY |
15 | |
16 | #define PT_PRESENT_MASK (1ULL << 0) | |
17 | #define PT_WRITABLE_MASK (1ULL << PT_WRITABLE_SHIFT) | |
be94f6b7 | 18 | #define PT_USER_MASK (1ULL << PT_USER_SHIFT) |
8c6d6adc SY |
19 | #define PT_PWT_MASK (1ULL << 3) |
20 | #define PT_PCD_MASK (1ULL << 4) | |
1b7fcd32 AK |
21 | #define PT_ACCESSED_SHIFT 5 |
22 | #define PT_ACCESSED_MASK (1ULL << PT_ACCESSED_SHIFT) | |
8ea667f2 AK |
23 | #define PT_DIRTY_SHIFT 6 |
24 | #define PT_DIRTY_MASK (1ULL << PT_DIRTY_SHIFT) | |
6fd01b71 AK |
25 | #define PT_PAGE_SIZE_SHIFT 7 |
26 | #define PT_PAGE_SIZE_MASK (1ULL << PT_PAGE_SIZE_SHIFT) | |
8c6d6adc SY |
27 | #define PT_PAT_MASK (1ULL << 7) |
28 | #define PT_GLOBAL_MASK (1ULL << 8) | |
29 | #define PT64_NX_SHIFT 63 | |
30 | #define PT64_NX_MASK (1ULL << PT64_NX_SHIFT) | |
31 | ||
32 | #define PT_PAT_SHIFT 7 | |
33 | #define PT_DIR_PAT_SHIFT 12 | |
34 | #define PT_DIR_PAT_MASK (1ULL << PT_DIR_PAT_SHIFT) | |
35 | ||
36 | #define PT32_DIR_PSE36_SIZE 4 | |
37 | #define PT32_DIR_PSE36_SHIFT 13 | |
38 | #define PT32_DIR_PSE36_MASK \ | |
39 | (((1ULL << PT32_DIR_PSE36_SIZE) - 1) << PT32_DIR_PSE36_SHIFT) | |
40 | ||
855feb67 | 41 | #define PT64_ROOT_5LEVEL 5 |
2a7266a8 | 42 | #define PT64_ROOT_4LEVEL 4 |
8c6d6adc SY |
43 | #define PT32_ROOT_LEVEL 2 |
44 | #define PT32E_ROOT_LEVEL 3 | |
45 | ||
d1431483 TC |
46 | static inline u64 rsvd_bits(int s, int e) |
47 | { | |
d1cd3ce9 YZ |
48 | if (e < s) |
49 | return 0; | |
50 | ||
d1431483 TC |
51 | return ((1ULL << (e - s + 1)) - 1) << s; |
52 | } | |
53 | ||
4af77151 | 54 | void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value, u64 access_mask); |
b37fbea6 | 55 | |
c258b62b XG |
56 | void |
57 | reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context); | |
58 | ||
1c53da3f | 59 | void kvm_init_mmu(struct kvm_vcpu *vcpu, bool reset_roots); |
ad896af0 | 60 | void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu); |
ae1e2d10 | 61 | void kvm_init_shadow_ept_mmu(struct kvm_vcpu *vcpu, bool execonly, |
50c28f21 | 62 | bool accessed_dirty, gpa_t new_eptp); |
9bc1f09f | 63 | bool kvm_can_do_async_pf(struct kvm_vcpu *vcpu); |
1261bfa3 | 64 | int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, |
d0006530 | 65 | u64 fault_address, char *insn, int insn_len); |
94d8b056 | 66 | |
bc8a3d89 | 67 | static inline unsigned long kvm_mmu_available_pages(struct kvm *kvm) |
e0df7b9f | 68 | { |
5d218814 MT |
69 | if (kvm->arch.n_max_mmu_pages > kvm->arch.n_used_mmu_pages) |
70 | return kvm->arch.n_max_mmu_pages - | |
71 | kvm->arch.n_used_mmu_pages; | |
72 | ||
73 | return 0; | |
e0df7b9f DH |
74 | } |
75 | ||
1d737c8a ZX |
76 | static inline int kvm_mmu_reload(struct kvm_vcpu *vcpu) |
77 | { | |
44dd3ffa | 78 | if (likely(vcpu->arch.mmu->root_hpa != INVALID_PAGE)) |
1d737c8a ZX |
79 | return 0; |
80 | ||
81 | return kvm_mmu_load(vcpu); | |
82 | } | |
83 | ||
c9470a2e JS |
84 | static inline unsigned long kvm_get_pcid(struct kvm_vcpu *vcpu, gpa_t cr3) |
85 | { | |
86 | BUILD_BUG_ON((X86_CR3_PCID_MASK & PAGE_MASK) != 0); | |
87 | ||
88 | return kvm_read_cr4_bits(vcpu, X86_CR4_PCIDE) | |
89 | ? cr3 & X86_CR3_PCID_MASK | |
90 | : 0; | |
91 | } | |
92 | ||
93 | static inline unsigned long kvm_get_active_pcid(struct kvm_vcpu *vcpu) | |
94 | { | |
95 | return kvm_get_pcid(vcpu, kvm_read_cr3(vcpu)); | |
96 | } | |
97 | ||
6e42782f JS |
98 | static inline void kvm_mmu_load_cr3(struct kvm_vcpu *vcpu) |
99 | { | |
44dd3ffa VK |
100 | if (VALID_PAGE(vcpu->arch.mmu->root_hpa)) |
101 | vcpu->arch.mmu->set_cr3(vcpu, vcpu->arch.mmu->root_hpa | | |
102 | kvm_get_active_pcid(vcpu)); | |
6e42782f JS |
103 | } |
104 | ||
7a02674d SC |
105 | int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code, |
106 | bool prefault); | |
107 | ||
108 | static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, | |
109 | u32 err, bool prefault) | |
110 | { | |
111 | #ifdef CONFIG_RETPOLINE | |
112 | if (likely(vcpu->arch.mmu->page_fault == kvm_tdp_page_fault)) | |
113 | return kvm_tdp_page_fault(vcpu, cr2_or_gpa, err, prefault); | |
114 | #endif | |
115 | return vcpu->arch.mmu->page_fault(vcpu, cr2_or_gpa, err, prefault); | |
116 | } | |
117 | ||
198c74f4 XG |
118 | /* |
119 | * Currently, we have two sorts of write-protection, a) the first one | |
120 | * write-protects guest page to sync the guest modification, b) another one is | |
121 | * used to sync dirty bitmap when we do KVM_GET_DIRTY_LOG. The differences | |
122 | * between these two sorts are: | |
123 | * 1) the first case clears SPTE_MMU_WRITEABLE bit. | |
124 | * 2) the first case requires flushing tlb immediately avoiding corrupting | |
125 | * shadow page table between all vcpus so it should be in the protection of | |
126 | * mmu-lock. And the another case does not need to flush tlb until returning | |
127 | * the dirty bitmap to userspace since it only write-protects the page | |
128 | * logged in the bitmap, that means the page in the dirty bitmap is not | |
129 | * missed, so it can flush tlb out of mmu-lock. | |
130 | * | |
131 | * So, there is the problem: the first case can meet the corrupted tlb caused | |
132 | * by another case which write-protects pages but without flush tlb | |
133 | * immediately. In order to making the first case be aware this problem we let | |
134 | * it flush tlb if we try to write-protect a spte whose SPTE_MMU_WRITEABLE bit | |
135 | * is set, it works since another case never touches SPTE_MMU_WRITEABLE bit. | |
136 | * | |
137 | * Anyway, whenever a spte is updated (only permission and status bits are | |
138 | * changed) we need to check whether the spte with SPTE_MMU_WRITEABLE becomes | |
139 | * readonly, if that happens, we need to flush tlb. Fortunately, | |
140 | * mmu_spte_update() has already handled it perfectly. | |
141 | * | |
142 | * The rules to use SPTE_MMU_WRITEABLE and PT_WRITABLE_MASK: | |
143 | * - if we want to see if it has writable tlb entry or if the spte can be | |
144 | * writable on the mmu mapping, check SPTE_MMU_WRITEABLE, this is the most | |
145 | * case, otherwise | |
146 | * - if we fix page fault on the spte or do write-protection by dirty logging, | |
147 | * check PT_WRITABLE_MASK. | |
148 | * | |
149 | * TODO: introduce APIs to split these two cases. | |
150 | */ | |
bebb106a XG |
151 | static inline int is_writable_pte(unsigned long pte) |
152 | { | |
153 | return pte & PT_WRITABLE_MASK; | |
154 | } | |
155 | ||
156 | static inline bool is_write_protection(struct kvm_vcpu *vcpu) | |
157 | { | |
158 | return kvm_read_cr0_bits(vcpu, X86_CR0_WP); | |
159 | } | |
160 | ||
97d64b78 | 161 | /* |
f13577e8 PB |
162 | * Check if a given access (described through the I/D, W/R and U/S bits of a |
163 | * page fault error code pfec) causes a permission fault with the given PTE | |
164 | * access rights (in ACC_* format). | |
165 | * | |
166 | * Return zero if the access does not fault; return the page fault error code | |
167 | * if the access faults. | |
97d64b78 | 168 | */ |
f13577e8 | 169 | static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, |
be94f6b7 HH |
170 | unsigned pte_access, unsigned pte_pkey, |
171 | unsigned pfec) | |
bebb106a | 172 | { |
97ec8c06 FW |
173 | int cpl = kvm_x86_ops->get_cpl(vcpu); |
174 | unsigned long rflags = kvm_x86_ops->get_rflags(vcpu); | |
175 | ||
176 | /* | |
177 | * If CPL < 3, SMAP prevention are disabled if EFLAGS.AC = 1. | |
178 | * | |
179 | * If CPL = 3, SMAP applies to all supervisor-mode data accesses | |
180 | * (these are implicit supervisor accesses) regardless of the value | |
181 | * of EFLAGS.AC. | |
182 | * | |
183 | * This computes (cpl < 3) && (rflags & X86_EFLAGS_AC), leaving | |
184 | * the result in X86_EFLAGS_AC. We then insert it in place of | |
185 | * the PFERR_RSVD_MASK bit; this bit will always be zero in pfec, | |
186 | * but it will be one in index if SMAP checks are being overridden. | |
187 | * It is important to keep this branchless. | |
188 | */ | |
189 | unsigned long smap = (cpl - 3) & (rflags & X86_EFLAGS_AC); | |
190 | int index = (pfec >> 1) + | |
191 | (smap >> (X86_EFLAGS_AC_BIT - PFERR_RSVD_BIT + 1)); | |
be94f6b7 | 192 | bool fault = (mmu->permissions[index] >> pte_access) & 1; |
7a98205d | 193 | u32 errcode = PFERR_PRESENT_MASK; |
97ec8c06 | 194 | |
be94f6b7 | 195 | WARN_ON(pfec & (PFERR_PK_MASK | PFERR_RSVD_MASK)); |
be94f6b7 HH |
196 | if (unlikely(mmu->pkru_mask)) { |
197 | u32 pkru_bits, offset; | |
198 | ||
199 | /* | |
200 | * PKRU defines 32 bits, there are 16 domains and 2 | |
201 | * attribute bits per domain in pkru. pte_pkey is the | |
202 | * index of the protection domain, so pte_pkey * 2 is | |
203 | * is the index of the first bit for the domain. | |
204 | */ | |
b9dd21e1 | 205 | pkru_bits = (vcpu->arch.pkru >> (pte_pkey * 2)) & 3; |
be94f6b7 HH |
206 | |
207 | /* clear present bit, replace PFEC.RSVD with ACC_USER_MASK. */ | |
7a98205d | 208 | offset = (pfec & ~1) + |
be94f6b7 HH |
209 | ((pte_access & PT_USER_MASK) << (PFERR_RSVD_BIT - PT_USER_SHIFT)); |
210 | ||
211 | pkru_bits &= mmu->pkru_mask >> offset; | |
7a98205d | 212 | errcode |= -pkru_bits & PFERR_PK_MASK; |
be94f6b7 HH |
213 | fault |= (pkru_bits != 0); |
214 | } | |
215 | ||
7a98205d | 216 | return -(u32)fault & errcode; |
bebb106a | 217 | } |
97d64b78 | 218 | |
efdfe536 | 219 | void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end); |
547ffaed XG |
220 | |
221 | void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn); | |
222 | void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn); | |
aeecee2e XG |
223 | bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, |
224 | struct kvm_memory_slot *slot, u64 gfn); | |
bab4165e | 225 | int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu); |
1aa9b957 JS |
226 | |
227 | int kvm_mmu_post_init_vm(struct kvm *kvm); | |
228 | void kvm_mmu_pre_destroy_vm(struct kvm *kvm); | |
229 | ||
1d737c8a | 230 | #endif |