arch/arm64/include/asm/kvm_mmu.h

   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__ */