1 /* 2 * Copyright (C) 2012,2013 - ARM Ltd 3 * Author: Marc Zyngier <marc.zyngier@arm.com> 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 18 #ifndef __ARM64_KVM_MMU_H__ 19 #define __ARM64_KVM_MMU_H__ 20 21 #include <asm/page.h> 22 #include <asm/memory.h> 23 #include <asm/cpufeature.h> 24 25 /* 26 * As ARMv8.0 only has the TTBR0_EL2 register, we cannot express 27 * "negative" addresses. This makes it impossible to directly share 28 * mappings with the kernel. 29 * 30 * Instead, give the HYP mode its own VA region at a fixed offset from 31 * the kernel by just masking the top bits (which are all ones for a 32 * kernel address). 33 * 34 * ARMv8.1 (using VHE) does have a TTBR1_EL2, and doesn't use these 35 * macros (the entire kernel runs at EL2). 36 */ 37 #define HYP_PAGE_OFFSET_SHIFT VA_BITS 38 #define HYP_PAGE_OFFSET_MASK ((UL(1) << HYP_PAGE_OFFSET_SHIFT) - 1) 39 #define HYP_PAGE_OFFSET (PAGE_OFFSET & HYP_PAGE_OFFSET_MASK) 40 41 /* 42 * Our virtual mapping for the idmap-ed MMU-enable code. Must be 43 * shared across all the page-tables. Conveniently, we use the last 44 * possible page, where no kernel mapping will ever exist. 45 */ 46 #define TRAMPOLINE_VA (HYP_PAGE_OFFSET_MASK & PAGE_MASK) 47 48 #ifdef __ASSEMBLY__ 49 50 #include <asm/alternative.h> 51 #include <asm/cpufeature.h> 52 53 /* 54 * Convert a kernel VA into a HYP VA. 55 * reg: VA to be converted. 56 */ 57 .macro kern_hyp_va reg 58 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN 59 and \reg, \reg, #HYP_PAGE_OFFSET_MASK 60 alternative_else 61 nop 62 alternative_endif 63 .endm 64 65 #else 66 67 #include <asm/pgalloc.h> 68 #include <asm/cachetype.h> 69 #include <asm/cacheflush.h> 70 #include <asm/mmu_context.h> 71 #include <asm/pgtable.h> 72 73 #define KERN_TO_HYP(kva) ((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET) 74 75 /* 76 * We currently only support a 40bit IPA. 77 */ 78 #define KVM_PHYS_SHIFT (40) 79 #define KVM_PHYS_SIZE (1UL << KVM_PHYS_SHIFT) 80 #define KVM_PHYS_MASK (KVM_PHYS_SIZE - 1UL) 81 82 #include <asm/stage2_pgtable.h> 83 84 int create_hyp_mappings(void *from, void *to); 85 int create_hyp_io_mappings(void *from, void *to, phys_addr_t); 86 void free_boot_hyp_pgd(void); 87 void free_hyp_pgds(void); 88 89 void stage2_unmap_vm(struct kvm *kvm); 90 int kvm_alloc_stage2_pgd(struct kvm *kvm); 91 void kvm_free_stage2_pgd(struct kvm *kvm); 92 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, 93 phys_addr_t pa, unsigned long size, bool writable); 94 95 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run); 96 97 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu); 98 99 phys_addr_t kvm_mmu_get_httbr(void); 100 phys_addr_t kvm_mmu_get_boot_httbr(void); 101 phys_addr_t kvm_get_idmap_vector(void); 102 phys_addr_t kvm_get_idmap_start(void); 103 int kvm_mmu_init(void); 104 void kvm_clear_hyp_idmap(void); 105 106 #define kvm_set_pte(ptep, pte) set_pte(ptep, pte) 107 #define kvm_set_pmd(pmdp, pmd) set_pmd(pmdp, pmd) 108 109 static inline void kvm_clean_pgd(pgd_t *pgd) {} 110 static inline void kvm_clean_pmd(pmd_t *pmd) {} 111 static inline void kvm_clean_pmd_entry(pmd_t *pmd) {} 112 static inline void kvm_clean_pte(pte_t *pte) {} 113 static inline void kvm_clean_pte_entry(pte_t *pte) {} 114 115 static inline pte_t kvm_s2pte_mkwrite(pte_t pte) 116 { 117 pte_val(pte) |= PTE_S2_RDWR; 118 return pte; 119 } 120 121 static inline pmd_t kvm_s2pmd_mkwrite(pmd_t pmd) 122 { 123 pmd_val(pmd) |= PMD_S2_RDWR; 124 return pmd; 125 } 126 127 static inline void kvm_set_s2pte_readonly(pte_t *pte) 128 { 129 pteval_t pteval; 130 unsigned long tmp; 131 132 asm volatile("// kvm_set_s2pte_readonly\n" 133 " prfm pstl1strm, %2\n" 134 "1: ldxr %0, %2\n" 135 " and %0, %0, %3 // clear PTE_S2_RDWR\n" 136 " orr %0, %0, %4 // set PTE_S2_RDONLY\n" 137 " stxr %w1, %0, %2\n" 138 " cbnz %w1, 1b\n" 139 : "=&r" (pteval), "=&r" (tmp), "+Q" (pte_val(*pte)) 140 : "L" (~PTE_S2_RDWR), "L" (PTE_S2_RDONLY)); 141 } 142 143 static inline bool kvm_s2pte_readonly(pte_t *pte) 144 { 145 return (pte_val(*pte) & PTE_S2_RDWR) == PTE_S2_RDONLY; 146 } 147 148 static inline void kvm_set_s2pmd_readonly(pmd_t *pmd) 149 { 150 kvm_set_s2pte_readonly((pte_t *)pmd); 151 } 152 153 static inline bool kvm_s2pmd_readonly(pmd_t *pmd) 154 { 155 return kvm_s2pte_readonly((pte_t *)pmd); 156 } 157 158 static inline bool kvm_page_empty(void *ptr) 159 { 160 struct page *ptr_page = virt_to_page(ptr); 161 return page_count(ptr_page) == 1; 162 } 163 164 #define hyp_pte_table_empty(ptep) kvm_page_empty(ptep) 165 166 #ifdef __PAGETABLE_PMD_FOLDED 167 #define hyp_pmd_table_empty(pmdp) (0) 168 #else 169 #define hyp_pmd_table_empty(pmdp) kvm_page_empty(pmdp) 170 #endif 171 172 #ifdef __PAGETABLE_PUD_FOLDED 173 #define hyp_pud_table_empty(pudp) (0) 174 #else 175 #define hyp_pud_table_empty(pudp) kvm_page_empty(pudp) 176 #endif 177 178 struct kvm; 179 180 #define kvm_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l)) 181 182 static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu) 183 { 184 return (vcpu_sys_reg(vcpu, SCTLR_EL1) & 0b101) == 0b101; 185 } 186 187 static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu, 188 kvm_pfn_t pfn, 189 unsigned long size, 190 bool ipa_uncached) 191 { 192 void *va = page_address(pfn_to_page(pfn)); 193 194 if (!vcpu_has_cache_enabled(vcpu) || ipa_uncached) 195 kvm_flush_dcache_to_poc(va, size); 196 197 if (!icache_is_aliasing()) { /* PIPT */ 198 flush_icache_range((unsigned long)va, 199 (unsigned long)va + size); 200 } else if (!icache_is_aivivt()) { /* non ASID-tagged VIVT */ 201 /* any kind of VIPT cache */ 202 __flush_icache_all(); 203 } 204 } 205 206 static inline void __kvm_flush_dcache_pte(pte_t pte) 207 { 208 struct page *page = pte_page(pte); 209 kvm_flush_dcache_to_poc(page_address(page), PAGE_SIZE); 210 } 211 212 static inline void __kvm_flush_dcache_pmd(pmd_t pmd) 213 { 214 struct page *page = pmd_page(pmd); 215 kvm_flush_dcache_to_poc(page_address(page), PMD_SIZE); 216 } 217 218 static inline void __kvm_flush_dcache_pud(pud_t pud) 219 { 220 struct page *page = pud_page(pud); 221 kvm_flush_dcache_to_poc(page_address(page), PUD_SIZE); 222 } 223 224 #define kvm_virt_to_phys(x) __virt_to_phys((unsigned long)(x)) 225 226 void kvm_set_way_flush(struct kvm_vcpu *vcpu); 227 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled); 228 229 static inline bool __kvm_cpu_uses_extended_idmap(void) 230 { 231 return __cpu_uses_extended_idmap(); 232 } 233 234 static inline void __kvm_extend_hypmap(pgd_t *boot_hyp_pgd, 235 pgd_t *hyp_pgd, 236 pgd_t *merged_hyp_pgd, 237 unsigned long hyp_idmap_start) 238 { 239 int idmap_idx; 240 241 /* 242 * Use the first entry to access the HYP mappings. It is 243 * guaranteed to be free, otherwise we wouldn't use an 244 * extended idmap. 245 */ 246 VM_BUG_ON(pgd_val(merged_hyp_pgd[0])); 247 merged_hyp_pgd[0] = __pgd(__pa(hyp_pgd) | PMD_TYPE_TABLE); 248 249 /* 250 * Create another extended level entry that points to the boot HYP map, 251 * which contains an ID mapping of the HYP init code. We essentially 252 * merge the boot and runtime HYP maps by doing so, but they don't 253 * overlap anyway, so this is fine. 254 */ 255 idmap_idx = hyp_idmap_start >> VA_BITS; 256 VM_BUG_ON(pgd_val(merged_hyp_pgd[idmap_idx])); 257 merged_hyp_pgd[idmap_idx] = __pgd(__pa(boot_hyp_pgd) | PMD_TYPE_TABLE); 258 } 259 260 static inline unsigned int kvm_get_vmid_bits(void) 261 { 262 int reg = read_system_reg(SYS_ID_AA64MMFR1_EL1); 263 264 return (cpuid_feature_extract_unsigned_field(reg, ID_AA64MMFR1_VMIDBITS_SHIFT) == 2) ? 16 : 8; 265 } 266 267 #endif /* __ASSEMBLY__ */ 268 #endif /* __ARM64_KVM_MMU_H__ */ 269