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