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/fixed_config.h> 16 #include <nvhe/gfp.h> 17 #include <nvhe/memory.h> 18 #include <nvhe/mem_protect.h> 19 #include <nvhe/mm.h> 20 #include <nvhe/pkvm.h> 21 #include <nvhe/trap_handler.h> 22 23 unsigned long hyp_nr_cpus; 24 25 #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ 26 (unsigned long)__per_cpu_start) 27 28 static void *vmemmap_base; 29 static void *vm_table_base; 30 static void *hyp_pgt_base; 31 static void *host_s2_pgt_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 = hyp_vmemmap_pages(sizeof(struct hyp_page)); 43 vmemmap_base = hyp_early_alloc_contig(nr_pages); 44 if (!vmemmap_base) 45 return -ENOMEM; 46 47 nr_pages = hyp_vm_table_pages(); 48 vm_table_base = hyp_early_alloc_contig(nr_pages); 49 if (!vm_table_base) 50 return -ENOMEM; 51 52 nr_pages = hyp_s1_pgtable_pages(); 53 hyp_pgt_base = hyp_early_alloc_contig(nr_pages); 54 if (!hyp_pgt_base) 55 return -ENOMEM; 56 57 nr_pages = host_s2_pgtable_pages(); 58 host_s2_pgt_base = hyp_early_alloc_contig(nr_pages); 59 if (!host_s2_pgt_base) 60 return -ENOMEM; 61 62 nr_pages = hyp_ffa_proxy_pages(); 63 ffa_proxy_pages = hyp_early_alloc_contig(nr_pages); 64 if (!ffa_proxy_pages) 65 return -ENOMEM; 66 67 return 0; 68 } 69 70 static int pkvm_create_host_sve_mappings(void) 71 { 72 void *start, *end; 73 int ret, i; 74 75 if (!system_supports_sve()) 76 return 0; 77 78 for (i = 0; i < hyp_nr_cpus; i++) { 79 struct kvm_host_data *host_data = per_cpu_ptr(&kvm_host_data, i); 80 struct cpu_sve_state *sve_state = host_data->sve_state; 81 82 start = kern_hyp_va(sve_state); 83 end = start + PAGE_ALIGN(pkvm_host_sve_state_size()); 84 ret = pkvm_create_mappings(start, end, PAGE_HYP); 85 if (ret) 86 return ret; 87 } 88 89 return 0; 90 } 91 92 static int recreate_hyp_mappings(phys_addr_t phys, unsigned long size, 93 unsigned long *per_cpu_base, 94 u32 hyp_va_bits) 95 { 96 void *start, *end, *virt = hyp_phys_to_virt(phys); 97 unsigned long pgt_size = hyp_s1_pgtable_pages() << PAGE_SHIFT; 98 enum kvm_pgtable_prot prot; 99 int ret, i; 100 101 /* Recreate the hyp page-table using the early page allocator */ 102 hyp_early_alloc_init(hyp_pgt_base, pgt_size); 103 ret = kvm_pgtable_hyp_init(&pkvm_pgtable, hyp_va_bits, 104 &hyp_early_alloc_mm_ops); 105 if (ret) 106 return ret; 107 108 ret = hyp_create_idmap(hyp_va_bits); 109 if (ret) 110 return ret; 111 112 ret = hyp_map_vectors(); 113 if (ret) 114 return ret; 115 116 ret = hyp_back_vmemmap(hyp_virt_to_phys(vmemmap_base)); 117 if (ret) 118 return ret; 119 120 ret = pkvm_create_mappings(__hyp_text_start, __hyp_text_end, PAGE_HYP_EXEC); 121 if (ret) 122 return ret; 123 124 ret = pkvm_create_mappings(__hyp_rodata_start, __hyp_rodata_end, PAGE_HYP_RO); 125 if (ret) 126 return ret; 127 128 ret = pkvm_create_mappings(__hyp_bss_start, __hyp_bss_end, PAGE_HYP); 129 if (ret) 130 return ret; 131 132 ret = pkvm_create_mappings(virt, virt + size, PAGE_HYP); 133 if (ret) 134 return ret; 135 136 for (i = 0; i < hyp_nr_cpus; i++) { 137 struct kvm_nvhe_init_params *params = per_cpu_ptr(&kvm_init_params, i); 138 139 start = (void *)kern_hyp_va(per_cpu_base[i]); 140 end = start + PAGE_ALIGN(hyp_percpu_size); 141 ret = pkvm_create_mappings(start, end, PAGE_HYP); 142 if (ret) 143 return ret; 144 145 ret = pkvm_create_stack(params->stack_pa, ¶ms->stack_hyp_va); 146 if (ret) 147 return ret; 148 } 149 150 pkvm_create_host_sve_mappings(); 151 152 /* 153 * Map the host sections RO in the hypervisor, but transfer the 154 * ownership from the host to the hypervisor itself to make sure they 155 * can't be donated or shared with another entity. 156 * 157 * The ownership transition requires matching changes in the host 158 * stage-2. This will be done later (see finalize_host_mappings()) once 159 * the hyp_vmemmap is addressable. 160 */ 161 prot = pkvm_mkstate(PAGE_HYP_RO, PKVM_PAGE_SHARED_OWNED); 162 ret = pkvm_create_mappings(&kvm_vgic_global_state, 163 &kvm_vgic_global_state + 1, prot); 164 if (ret) 165 return ret; 166 167 return 0; 168 } 169 170 static void update_nvhe_init_params(void) 171 { 172 struct kvm_nvhe_init_params *params; 173 unsigned long i; 174 175 for (i = 0; i < hyp_nr_cpus; i++) { 176 params = per_cpu_ptr(&kvm_init_params, i); 177 params->pgd_pa = __hyp_pa(pkvm_pgtable.pgd); 178 dcache_clean_inval_poc((unsigned long)params, 179 (unsigned long)params + sizeof(*params)); 180 } 181 } 182 183 static void *hyp_zalloc_hyp_page(void *arg) 184 { 185 return hyp_alloc_pages(&hpool, 0); 186 } 187 188 static void hpool_get_page(void *addr) 189 { 190 hyp_get_page(&hpool, addr); 191 } 192 193 static void hpool_put_page(void *addr) 194 { 195 hyp_put_page(&hpool, addr); 196 } 197 198 static int fix_host_ownership_walker(const struct kvm_pgtable_visit_ctx *ctx, 199 enum kvm_pgtable_walk_flags visit) 200 { 201 enum kvm_pgtable_prot prot; 202 enum pkvm_page_state state; 203 phys_addr_t phys; 204 205 if (!kvm_pte_valid(ctx->old)) 206 return 0; 207 208 if (ctx->level != KVM_PGTABLE_LAST_LEVEL) 209 return -EINVAL; 210 211 phys = kvm_pte_to_phys(ctx->old); 212 if (!addr_is_memory(phys)) 213 return -EINVAL; 214 215 /* 216 * Adjust the host stage-2 mappings to match the ownership attributes 217 * configured in the hypervisor stage-1. 218 */ 219 state = pkvm_getstate(kvm_pgtable_hyp_pte_prot(ctx->old)); 220 switch (state) { 221 case PKVM_PAGE_OWNED: 222 return host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_HYP); 223 case PKVM_PAGE_SHARED_OWNED: 224 prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_BORROWED); 225 break; 226 case PKVM_PAGE_SHARED_BORROWED: 227 prot = pkvm_mkstate(PKVM_HOST_MEM_PROT, PKVM_PAGE_SHARED_OWNED); 228 break; 229 default: 230 return -EINVAL; 231 } 232 233 return host_stage2_idmap_locked(phys, PAGE_SIZE, prot); 234 } 235 236 static int fix_hyp_pgtable_refcnt_walker(const struct kvm_pgtable_visit_ctx *ctx, 237 enum kvm_pgtable_walk_flags visit) 238 { 239 /* 240 * Fix-up the refcount for the page-table pages as the early allocator 241 * was unable to access the hyp_vmemmap and so the buddy allocator has 242 * initialised the refcount to '1'. 243 */ 244 if (kvm_pte_valid(ctx->old)) 245 ctx->mm_ops->get_page(ctx->ptep); 246 247 return 0; 248 } 249 250 static int fix_host_ownership(void) 251 { 252 struct kvm_pgtable_walker walker = { 253 .cb = fix_host_ownership_walker, 254 .flags = KVM_PGTABLE_WALK_LEAF, 255 }; 256 int i, ret; 257 258 for (i = 0; i < hyp_memblock_nr; i++) { 259 struct memblock_region *reg = &hyp_memory[i]; 260 u64 start = (u64)hyp_phys_to_virt(reg->base); 261 262 ret = kvm_pgtable_walk(&pkvm_pgtable, start, reg->size, &walker); 263 if (ret) 264 return ret; 265 } 266 267 return 0; 268 } 269 270 static int fix_hyp_pgtable_refcnt(void) 271 { 272 struct kvm_pgtable_walker walker = { 273 .cb = fix_hyp_pgtable_refcnt_walker, 274 .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, 275 .arg = pkvm_pgtable.mm_ops, 276 }; 277 278 return kvm_pgtable_walk(&pkvm_pgtable, 0, BIT(pkvm_pgtable.ia_bits), 279 &walker); 280 } 281 282 void __noreturn __pkvm_init_finalise(void) 283 { 284 struct kvm_cpu_context *host_ctxt = host_data_ptr(host_ctxt); 285 unsigned long nr_pages, reserved_pages, pfn; 286 int ret; 287 288 /* Now that the vmemmap is backed, install the full-fledged allocator */ 289 pfn = hyp_virt_to_pfn(hyp_pgt_base); 290 nr_pages = hyp_s1_pgtable_pages(); 291 reserved_pages = hyp_early_alloc_nr_used_pages(); 292 ret = hyp_pool_init(&hpool, pfn, nr_pages, reserved_pages); 293 if (ret) 294 goto out; 295 296 ret = kvm_host_prepare_stage2(host_s2_pgt_base); 297 if (ret) 298 goto out; 299 300 pkvm_pgtable_mm_ops = (struct kvm_pgtable_mm_ops) { 301 .zalloc_page = hyp_zalloc_hyp_page, 302 .phys_to_virt = hyp_phys_to_virt, 303 .virt_to_phys = hyp_virt_to_phys, 304 .get_page = hpool_get_page, 305 .put_page = hpool_put_page, 306 .page_count = hyp_page_count, 307 }; 308 pkvm_pgtable.mm_ops = &pkvm_pgtable_mm_ops; 309 310 ret = fix_host_ownership(); 311 if (ret) 312 goto out; 313 314 ret = fix_hyp_pgtable_refcnt(); 315 if (ret) 316 goto out; 317 318 ret = hyp_create_pcpu_fixmap(); 319 if (ret) 320 goto out; 321 322 ret = hyp_ffa_init(ffa_proxy_pages); 323 if (ret) 324 goto out; 325 326 pkvm_hyp_vm_table_init(vm_table_base); 327 out: 328 /* 329 * We tail-called to here from handle___pkvm_init() and will not return, 330 * so make sure to propagate the return value to the host. 331 */ 332 cpu_reg(host_ctxt, 1) = ret; 333 334 __host_enter(host_ctxt); 335 } 336 337 int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, 338 unsigned long *per_cpu_base, u32 hyp_va_bits) 339 { 340 struct kvm_nvhe_init_params *params; 341 void *virt = hyp_phys_to_virt(phys); 342 typeof(__pkvm_init_switch_pgd) *fn; 343 int ret; 344 345 BUG_ON(kvm_check_pvm_sysreg_table()); 346 347 if (!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(size)) 348 return -EINVAL; 349 350 hyp_spin_lock_init(&pkvm_pgd_lock); 351 hyp_nr_cpus = nr_cpus; 352 353 ret = divide_memory_pool(virt, size); 354 if (ret) 355 return ret; 356 357 ret = recreate_hyp_mappings(phys, size, per_cpu_base, hyp_va_bits); 358 if (ret) 359 return ret; 360 361 update_nvhe_init_params(); 362 363 /* Jump in the idmap page to switch to the new page-tables */ 364 params = this_cpu_ptr(&kvm_init_params); 365 fn = (typeof(fn))__hyp_pa(__pkvm_init_switch_pgd); 366 fn(params->pgd_pa, params->stack_hyp_va, __pkvm_init_finalise); 367 368 unreachable(); 369 } 370