1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2020 Google LLC 4 * Author: Quentin Perret <qperret@google.com> 5 */ 6 7 #include <linux/kvm_host.h> 8 #include <asm/kvm_hyp.h> 9 #include <asm/kvm_mmu.h> 10 #include <asm/kvm_pgtable.h> 11 #include <asm/kvm_pkvm.h> 12 13 #include <nvhe/early_alloc.h> 14 #include <nvhe/ffa.h> 15 #include <nvhe/gfp.h> 16 #include <nvhe/memory.h> 17 #include <nvhe/mem_protect.h> 18 #include <nvhe/mm.h> 19 #include <nvhe/pkvm.h> 20 #include <nvhe/trap_handler.h> 21 22 unsigned long hyp_nr_cpus; 23 24 #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ 25 (unsigned long)__per_cpu_start) 26 27 static void *vmemmap_base; 28 static void *vm_table_base; 29 static void *hyp_pgt_base; 30 static void *host_s2_pgt_base; 31 static void *selftest_base; 32 static void *ffa_proxy_pages; 33 static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; 34 static struct hyp_pool hpool; 35 36 static int divide_memory_pool(void *virt, unsigned long size) 37 { 38 unsigned long nr_pages; 39 40 hyp_early_alloc_init(virt, size); 41 42 nr_pages = pkvm_selftest_pages(); 43 selftest_base = hyp_early_alloc_contig(nr_pages); 44 if (nr_pages && !selftest_base) 45 return -ENOMEM; 46 47 nr_pages = hyp_vmemmap_pages(sizeof(struct hyp_page)); 48 vmemmap_base = hyp_early_alloc_contig(nr_pages); 49 if (!vmemmap_base) 50 return -ENOMEM; 51 52 nr_pages = hyp_vm_table_pages(); 53 vm_table_base = hyp_early_alloc_contig(nr_pages); 54 if (!vm_table_base) 55 return -ENOMEM; 56 57 nr_pages = hyp_s1_pgtable_pages(); 58 hyp_pgt_base = hyp_early_alloc_contig(nr_pages); 59 if (!hyp_pgt_base) 60 return -ENOMEM; 61 62 nr_pages = host_s2_pgtable_pages(); 63 host_s2_pgt_base = hyp_early_alloc_contig(nr_pages); 64 if (!host_s2_pgt_base) 65 return -ENOMEM; 66 67 nr_pages = hyp_ffa_proxy_pages(); 68 ffa_proxy_pages = hyp_early_alloc_contig(nr_pages); 69 if (!ffa_proxy_pages) 70 return -ENOMEM; 71 72 return 0; 73 } 74 75 static int pkvm_create_host_sve_mappings(void) 76 { 77 void *start, *end; 78 int ret, i; 79 80 if (!system_supports_sve()) 81 return 0; 82 83 for (i = 0; i < hyp_nr_cpus; i++) { 84 struct kvm_host_data *host_data = per_cpu_ptr(&kvm_host_data, i); 85 struct cpu_sve_state *sve_state = host_data->sve_state; 86 87 start = kern_hyp_va(sve_state); 88 end = start + PAGE_ALIGN(pkvm_host_sve_state_size()); 89 ret = pkvm_create_mappings(start, end, PAGE_HYP); 90 if (ret) 91 return ret; 92 } 93 94 return 0; 95 } 96 97 static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, 98 unsigned long *per_cpu_base, 99 u32 hyp_va_bits) 100 { 101 void *start, *end, *virt = hyp_phys_to_virt(phys); 102 unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; 103 int ret, i; 104 105 /* Recreate the hyp page-table using the early page allocator */ 106 hyp_early_alloc_init(hyp_pgt_base, pgt_size); 107 ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, 108 &hyp_early_alloc_mm_ops); 109 if (ret) 110 return ret; 111 112 ret = hyp_create_idmap(hyp_va_bits); 113 if (ret) 114 return ret; 115 116 ret = hyp_map_vectors(); 117 if (ret) 118 return ret; 119 120 ret = hyp_back_vmemmap(hyp_virt_to_phys(vmemmap_base)); 121 if (ret) 122 return ret; 123 124 ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); 125 if (ret) 126 return ret; 127 128 ret = pkvm_create_mappings(__hyp_data_start, __hyp_data_end, PAGE_HYP); 129 if (ret) 130 return ret; 131 132 ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); 133 if (ret) 134 return ret; 135 136 ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); 137 if (ret) 138 return ret; 139 140 ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); 141 if (ret) 142 return ret; 143 144 for (i = 0; i < hyp_nr_cpus; i++) { 145 struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i); 146 147 start = (void *)kern_hyp_va(per_cpu_base[i]); 148 end = start + PAGE_ALIGN(hyp_percpu_size); 149 ret = pkvm_create_mappings(start, end, PAGE_HYP); 150 if (ret) 151 return ret; 152 153 ret = pkvm_create_stack(params->stack_pa, ¶ms->stack_hyp_va); 154 if (ret) 155 return ret; 156 } 157 158 return pkvm_create_host_sve_mappings(); 159 } 160 161 static void update_nvhe_init_params(void) 162 { 163 struct kvm_nvhe_init_params *params; 164 unsigned long i; 165 166 for (i = 0; i < hyp_nr_cpus; i++) { 167 params = per_cpu_ptr(&kvm_init_params, i); 168 params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); 169 dcache_clean_inval_poc((unsigned long)params, 170 (unsigned long)params + sizeof(*params)); 171 } 172 } 173 174 static void *hyp_zalloc_hyp_page(void *arg) 175 { 176 return hyp_alloc_pages(&hpool, 0); 177 } 178 179 static void hpool_get_page(void *addr) 180 { 181 hyp_get_page(&hpool, addr); 182 } 183 184 static void hpool_put_page(void *addr) 185 { 186 hyp_put_page(&hpool, addr); 187 } 188 189 static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx, 190 enum kvm_pgtable_walk_flags visit) 191 { 192 enum pkvm_page_state state; 193 struct hyp_page *page; 194 phys_addr_t phys; 195 enum kvm_pgtable_prot prot; 196 197 if (!kvm_pte_valid(ctx->old)) 198 return 0; 199 200 if (ctx->level != KVM_PGTABLE_LAST_LEVEL) 201 return -EINVAL; 202 203 phys = kvm_pte_to_phys(ctx->old); 204 if (!addr_is_memory(phys)) 205 return -EINVAL; 206 207 page = hyp_phys_to_page(phys); 208 209 /* 210 * Adjust the host stage-2 mappings to match the ownership attributes 211 * configured in the hypervisor stage-1, and make sure to propagate them 212 * to the hyp_vmemmap state. 213 */ 214 prot = kvm_pgtable_hyp_pte_prot(ctx->old); 215 state = pkvm_getstate(prot); 216 switch (state) { 217 case PKVM_PAGE_OWNED: 218 set_hyp_state(page, PKVM_PAGE_OWNED); 219 /* hyp text is RO in the host stage-2 to be inspected on panic. */ 220 if (prot == PAGE_HYP_EXEC) { 221 set_host_state(page, PKVM_NOPAGE); 222 return host_stage2_idmap_locked(phys, PAGE_SIZE, KVM_PGTABLE_PROT_R); 223 } else { 224 return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP); 225 } 226 case PKVM_PAGE_SHARED_OWNED: 227 set_hyp_state(page, PKVM_PAGE_SHARED_OWNED); 228 set_host_state(page, PKVM_PAGE_SHARED_BORROWED); 229 break; 230 case PKVM_PAGE_SHARED_BORROWED: 231 set_hyp_state(page, PKVM_PAGE_SHARED_BORROWED); 232 set_host_state(page, PKVM_PAGE_SHARED_OWNED); 233 break; 234 default: 235 return -EINVAL; 236 } 237 238 return 0; 239 } 240 241 static int fix_hyp_pgtable_refcnt_walker(const struct kvm_pgtable_visit_ctx *ctx, 242 enum kvm_pgtable_walk_flags visit) 243 { 244 /* 245 * Fix-up the refcount for the page-table pages as the early allocator 246 * was unable to access the hyp_vmemmap and so the buddy allocator has 247 * initialised the refcount to '1'. 248 */ 249 if (kvm_pte_valid(ctx->old)) 250 ctx->mm_ops->get_page(ctx->ptep); 251 252 return 0; 253 } 254 255 static int fix_host_ownership(void) 256 { 257 struct kvm_pgtable_walker walker = { 258 .cb = fix_host_ownership_walker, 259 .flags = KVM_PGTABLE_WALK_LEAF, 260 }; 261 int i, ret; 262 263 for (i = 0; i < hyp_memblock_nr; i++) { 264 struct memblock_region *reg = &hyp_memory[i]; 265 u64 start = (u64)hyp_phys_to_virt(reg->base); 266 267 ret = kvm_pgtable_walk(&pkvm_pgtable, start, reg->size, &walker); 268 if (ret) 269 return ret; 270 } 271 272 return 0; 273 } 274 275 static int fix_hyp_pgtable_refcnt(void) 276 { 277 struct kvm_pgtable_walker walker = { 278 .cb = fix_hyp_pgtable_refcnt_walker, 279 .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, 280 .arg = pkvm_pgtable.mm_ops, 281 }; 282 283 return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), 284 &walker); 285 } 286 287 void __noreturn __pkvm_init_finalise(void) 288 { 289 struct kvm_cpu_context *host_ctxt = host_data_ptr(host_ctxt); 290 unsigned long nr_pages, reserved_pages, pfn; 291 int ret; 292 293 /* Now that the vmemmap is backed, install the full-fledged allocator */ 294 pfn = hyp_virt_to_pfn(hyp_pgt_base); 295 nr_pages = hyp_s1_pgtable_pages(); 296 reserved_pages = hyp_early_alloc_nr_used_pages(); 297 ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); 298 if (ret) 299 goto out; 300 301 ret = kvm_host_prepare_stage2(host_s2_pgt_base); 302 if (ret) 303 goto out; 304 305 pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { 306 .zalloc_page = hyp_zalloc_hyp_page, 307 .phys_to_virt = hyp_phys_to_virt, 308 .virt_to_phys = hyp_virt_to_phys, 309 .get_page = hpool_get_page, 310 .put_page = hpool_put_page, 311 .page_count = hyp_page_count, 312 }; 313 pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; 314 315 ret = fix_host_ownership(); 316 if (ret) 317 goto out; 318 319 ret = fix_hyp_pgtable_refcnt(); 320 if (ret) 321 goto out; 322 323 ret = hyp_create_fixmap(); 324 if (ret) 325 goto out; 326 327 ret = hyp_ffa_init(ffa_proxy_pages); 328 if (ret) 329 goto out; 330 331 pkvm_hyp_vm_table_init(vm_table_base); 332 333 pkvm_ownership_selftest(selftest_base); 334 out: 335 /* 336 * We tail-called to here from handle___pkvm_init() and will not return, 337 * so make sure to propagate the return value to the host. 338 */ 339 cpu_reg(host_ctxt, 1) = ret; 340 341 __host_enter(host_ctxt); 342 } 343 344 int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, 345 unsigned long *per_cpu_base, u32 hyp_va_bits) 346 { 347 struct kvm_nvhe_init_params *params; 348 void *virt = hyp_phys_to_virt(phys); 349 typeof(__pkvm_init_switch_pgd) *fn; 350 int ret; 351 352 BUG_ON(kvm_check_pvm_sysreg_table()); 353 354 if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) 355 return -EINVAL; 356 357 hyp_spin_lock_init(&pkvm_pgd_lock); 358 hyp_nr_cpus = nr_cpus; 359 360 ret = divide_memory_pool(virt, size); 361 if (ret) 362 return ret; 363 364 ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); 365 if (ret) 366 return ret; 367 368 update_nvhe_init_params(); 369 370 /* Jump in the idmap page to switch to the new page-tables */ 371 params = this_cpu_ptr(&kvm_init_params); 372 fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); 373 fn(params->pgd_pa, params->stack_hyp_va, __pkvm_init_finalise); 374 375 unreachable(); 376 } 377