arch/arm/include/asm/kvm_mmu.h

   1 /*
   2  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
   3  * Author: Christoffer Dall <c.dall@virtualopensystems.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, write to the Free Software
  16  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17  */
  18
  19 #ifndef __ARM_KVM_MMU_H__
  20 #define __ARM_KVM_MMU_H__
  21
  22 #include <asm/memory.h>
  23 #include <asm/page.h>
  24
  25 /*
  26  * We directly use the kernel VA for the HYP, as we can directly share
  27  * the mapping (HTTBR "covers" TTBR1).
  28  */
  29 #define kern_hyp_va(kva)        (kva)
  30
  31 /*
  32  * KVM_MMU_CACHE_MIN_PAGES is the number of stage2 page table translation levels.
  33  */
  34 #define KVM_MMU_CACHE_MIN_PAGES 2
  35
  36 #ifndef __ASSEMBLY__
  37
  38 #include <linux/highmem.h>
  39 #include <asm/cacheflush.h>
  40 #include <asm/pgalloc.h>
  41 #include <asm/stage2_pgtable.h>
  42
  43 int create_hyp_mappings(void *from, void *to, pgprot_t prot);
  44 int create_hyp_io_mappings(void *from, void *to, phys_addr_t);
  45 void free_hyp_pgds(void);
  46
  47 void stage2_unmap_vm(struct kvm *kvm);
  48 int kvm_alloc_stage2_pgd(struct kvm *kvm);
  49 void kvm_free_stage2_pgd(struct kvm *kvm);
  50 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
  51                           phys_addr_t pa, unsigned long size, bool writable);
  52
  53 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
  54
  55 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
  56
  57 phys_addr_t kvm_mmu_get_httbr(void);
  58 phys_addr_t kvm_get_idmap_vector(void);
  59 phys_addr_t kvm_get_idmap_start(void);
  60 int kvm_mmu_init(void);
  61 void kvm_clear_hyp_idmap(void);
  62
  63 static inline void kvm_set_pmd(pmd_t *pmd, pmd_t new_pmd)
  64 {
  65         *pmd = new_pmd;
  66         flush_pmd_entry(pmd);
  67 }
  68
  69 static inline void kvm_set_pte(pte_t *pte, pte_t new_pte)
  70 {
  71         *pte = new_pte;
  72         /*
  73          * flush_pmd_entry just takes a void pointer and cleans the necessary
  74          * cache entries, so we can reuse the function for ptes.
  75          */
  76         flush_pmd_entry(pte);
  77 }
  78
  79 static inline void kvm_clean_pgd(pgd_t *pgd)
  80 {
  81         clean_dcache_area(pgd, PTRS_PER_S2_PGD * sizeof(pgd_t));
  82 }
  83
  84 static inline void kvm_clean_pmd(pmd_t *pmd)
  85 {
  86         clean_dcache_area(pmd, PTRS_PER_PMD * sizeof(pmd_t));
  87 }
  88
  89 static inline void kvm_clean_pmd_entry(pmd_t *pmd)
  90 {
  91         clean_pmd_entry(pmd);
  92 }
  93
  94 static inline void kvm_clean_pte(pte_t *pte)
  95 {
  96         clean_pte_table(pte);
  97 }
  98
  99 static inline pte_t kvm_s2pte_mkwrite(pte_t pte)
 100 {
 101         pte_val(pte) |= L_PTE_S2_RDWR;
 102         return pte;
 103 }
 104
 105 static inline pmd_t kvm_s2pmd_mkwrite(pmd_t pmd)
 106 {
 107         pmd_val(pmd) |= L_PMD_S2_RDWR;
 108         return pmd;
 109 }
 110
 111 static inline void kvm_set_s2pte_readonly(pte_t *pte)
 112 {
 113         pte_val(*pte) = (pte_val(*pte) & ~L_PTE_S2_RDWR) | L_PTE_S2_RDONLY;
 114 }
 115
 116 static inline bool kvm_s2pte_readonly(pte_t *pte)
 117 {
 118         return (pte_val(*pte) & L_PTE_S2_RDWR) == L_PTE_S2_RDONLY;
 119 }
 120
 121 static inline void kvm_set_s2pmd_readonly(pmd_t *pmd)
 122 {
 123         pmd_val(*pmd) = (pmd_val(*pmd) & ~L_PMD_S2_RDWR) | L_PMD_S2_RDONLY;
 124 }
 125
 126 static inline bool kvm_s2pmd_readonly(pmd_t *pmd)
 127 {
 128         return (pmd_val(*pmd) & L_PMD_S2_RDWR) == L_PMD_S2_RDONLY;
 129 }
 130
 131 static inline bool kvm_page_empty(void *ptr)
 132 {
 133         struct page *ptr_page = virt_to_page(ptr);
 134         return page_count(ptr_page) == 1;
 135 }
 136
 137 #define kvm_pte_table_empty(kvm, ptep) kvm_page_empty(ptep)
 138 #define kvm_pmd_table_empty(kvm, pmdp) kvm_page_empty(pmdp)
 139 #define kvm_pud_table_empty(kvm, pudp) false
 140
 141 #define hyp_pte_table_empty(ptep) kvm_page_empty(ptep)
 142 #define hyp_pmd_table_empty(pmdp) kvm_page_empty(pmdp)
 143 #define hyp_pud_table_empty(pudp) false
 144
 145 struct kvm;
 146
 147 #define kvm_flush_dcache_to_poc(a,l)    __cpuc_flush_dcache_area((a), (l))
 148
 149 static inline bool vcpu_has_cache_enabled(struct kvm_vcpu *vcpu)
 150 {
 151         return (vcpu_cp15(vcpu, c1_SCTLR) & 0b101) == 0b101;
 152 }
 153
 154 static inline void __coherent_cache_guest_page(struct kvm_vcpu *vcpu,
 155                                                kvm_pfn_t pfn,
 156                                                unsigned long size,
 157                                                bool ipa_uncached)
 158 {
 159         /*
 160          * If we are going to insert an instruction page and the icache is
 161          * either VIPT or PIPT, there is a potential problem where the host
 162          * (or another VM) may have used the same page as this guest, and we
 163          * read incorrect data from the icache.  If we're using a PIPT cache,
 164          * we can invalidate just that page, but if we are using a VIPT cache
 165          * we need to invalidate the entire icache - damn shame - as written
 166          * in the ARM ARM (DDI 0406C.b - Page B3-1393).
 167          *
 168          * VIVT caches are tagged using both the ASID and the VMID and doesn't
 169          * need any kind of flushing (DDI 0406C.b - Page B3-1392).
 170          *
 171          * We need to do this through a kernel mapping (using the
 172          * user-space mapping has proved to be the wrong
 173          * solution). For that, we need to kmap one page at a time,
 174          * and iterate over the range.
 175          */
 176
 177         bool need_flush = !vcpu_has_cache_enabled(vcpu) || ipa_uncached;
 178
 179         VM_BUG_ON(size & ~PAGE_MASK);
 180
 181         if (!need_flush && !icache_is_pipt())
 182                 goto vipt_cache;
 183
 184         while (size) {
 185                 void *va = kmap_atomic_pfn(pfn);
 186
 187                 if (need_flush)
 188                         kvm_flush_dcache_to_poc(va, PAGE_SIZE);
 189
 190                 if (icache_is_pipt())
 191                         __cpuc_coherent_user_range((unsigned long)va,
 192                                                    (unsigned long)va + PAGE_SIZE);
 193
 194                 size -= PAGE_SIZE;
 195                 pfn++;
 196
 197                 kunmap_atomic(va);
 198         }
 199
 200 vipt_cache:
 201         if (!icache_is_pipt() && !icache_is_vivt_asid_tagged()) {
 202                 /* any kind of VIPT cache */
 203                 __flush_icache_all();
 204         }
 205 }
 206
 207 static inline void __kvm_flush_dcache_pte(pte_t pte)
 208 {
 209         void *va = kmap_atomic(pte_page(pte));
 210
 211         kvm_flush_dcache_to_poc(va, PAGE_SIZE);
 212
 213         kunmap_atomic(va);
 214 }
 215
 216 static inline void __kvm_flush_dcache_pmd(pmd_t pmd)
 217 {
 218         unsigned long size = PMD_SIZE;
 219         kvm_pfn_t pfn = pmd_pfn(pmd);
 220
 221         while (size) {
 222                 void *va = kmap_atomic_pfn(pfn);
 223
 224                 kvm_flush_dcache_to_poc(va, PAGE_SIZE);
 225
 226                 pfn++;
 227                 size -= PAGE_SIZE;
 228
 229                 kunmap_atomic(va);
 230         }
 231 }
 232
 233 static inline void __kvm_flush_dcache_pud(pud_t pud)
 234 {
 235 }
 236
 237 #define kvm_virt_to_phys(x)             virt_to_idmap((unsigned long)(x))
 238
 239 void kvm_set_way_flush(struct kvm_vcpu *vcpu);
 240 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);
 241
 242 static inline bool __kvm_cpu_uses_extended_idmap(void)
 243 {
 244         return false;
 245 }
 246
 247 static inline void __kvm_extend_hypmap(pgd_t *boot_hyp_pgd,
 248                                        pgd_t *hyp_pgd,
 249                                        pgd_t *merged_hyp_pgd,
 250                                        unsigned long hyp_idmap_start) { }
 251
 252 static inline unsigned int kvm_get_vmid_bits(void)
 253 {
 254         return 8;
 255 }
 256
 257 #endif  /* !__ASSEMBLY__ */
 258
 259 #endif /* __ARM_KVM_MMU_H__ */