1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * tboot.c: main implementation of helper functions used by kernel for 4 * runtime support of Intel(R) Trusted Execution Technology 5 * 6 * Copyright (c) 2006-2009, Intel Corporation 7 */ 8 9 #include <linux/intel-iommu.h> 10 #include <linux/init_task.h> 11 #include <linux/spinlock.h> 12 #include <linux/export.h> 13 #include <linux/delay.h> 14 #include <linux/sched.h> 15 #include <linux/init.h> 16 #include <linux/dmar.h> 17 #include <linux/cpu.h> 18 #include <linux/pfn.h> 19 #include <linux/mm.h> 20 #include <linux/tboot.h> 21 #include <linux/debugfs.h> 22 23 #include <asm/realmode.h> 24 #include <asm/processor.h> 25 #include <asm/bootparam.h> 26 #include <asm/pgalloc.h> 27 #include <asm/fixmap.h> 28 #include <asm/proto.h> 29 #include <asm/setup.h> 30 #include <asm/e820/api.h> 31 #include <asm/io.h> 32 33 #include "../realmode/rm/wakeup.h" 34 35 /* Global pointer to shared data; NULL means no measured launch. */ 36 static struct tboot *tboot __read_mostly; 37 38 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ 39 #define AP_WAIT_TIMEOUT 1 40 41 #undef pr_fmt 42 #define pr_fmt(fmt) "tboot: " fmt 43 44 static u8 tboot_uuid[16] __initdata = TBOOT_UUID; 45 46 bool tboot_enabled(void) 47 { 48 return tboot != NULL; 49 } 50 51 /* noinline to prevent gcc from warning about dereferencing constant fixaddr */ 52 static noinline __init bool check_tboot_version(void) 53 { 54 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { 55 pr_warn("tboot at 0x%llx is invalid\n", boot_params.tboot_addr); 56 return false; 57 } 58 59 if (tboot->version < 5) { 60 pr_warn("tboot version is invalid: %u\n", tboot->version); 61 return false; 62 } 63 64 pr_info("found shared page at phys addr 0x%llx:\n", 65 boot_params.tboot_addr); 66 pr_debug("version: %d\n", tboot->version); 67 pr_debug("log_addr: 0x%08x\n", tboot->log_addr); 68 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); 69 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); 70 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); 71 72 return true; 73 } 74 75 void __init tboot_probe(void) 76 { 77 /* Look for valid page-aligned address for shared page. */ 78 if (!boot_params.tboot_addr) 79 return; 80 /* 81 * also verify that it is mapped as we expect it before calling 82 * set_fixmap(), to reduce chance of garbage value causing crash 83 */ 84 if (!e820__mapped_any(boot_params.tboot_addr, 85 boot_params.tboot_addr, E820_TYPE_RESERVED)) { 86 pr_warn("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n"); 87 return; 88 } 89 90 /* Map and check for tboot UUID. */ 91 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); 92 tboot = (void *)fix_to_virt(FIX_TBOOT_BASE); 93 if (!check_tboot_version()) 94 tboot = NULL; 95 } 96 97 static pgd_t *tboot_pg_dir; 98 static struct mm_struct tboot_mm = { 99 .mm_rb = RB_ROOT, 100 .pgd = swapper_pg_dir, 101 .mm_users = ATOMIC_INIT(2), 102 .mm_count = ATOMIC_INIT(1), 103 .write_protect_seq = SEQCNT_ZERO(tboot_mm.write_protect_seq), 104 MMAP_LOCK_INITIALIZER(init_mm) 105 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), 106 .mmlist = LIST_HEAD_INIT(init_mm.mmlist), 107 }; 108 109 static inline void switch_to_tboot_pt(void) 110 { 111 write_cr3(virt_to_phys(tboot_pg_dir)); 112 } 113 114 static int map_tboot_page(unsigned long vaddr, unsigned long pfn, 115 pgprot_t prot) 116 { 117 pgd_t *pgd; 118 p4d_t *p4d; 119 pud_t *pud; 120 pmd_t *pmd; 121 pte_t *pte; 122 123 pgd = pgd_offset(&tboot_mm, vaddr); 124 p4d = p4d_alloc(&tboot_mm, pgd, vaddr); 125 if (!p4d) 126 return -1; 127 pud = pud_alloc(&tboot_mm, p4d, vaddr); 128 if (!pud) 129 return -1; 130 pmd = pmd_alloc(&tboot_mm, pud, vaddr); 131 if (!pmd) 132 return -1; 133 pte = pte_alloc_map(&tboot_mm, pmd, vaddr); 134 if (!pte) 135 return -1; 136 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); 137 pte_unmap(pte); 138 139 /* 140 * PTI poisons low addresses in the kernel page tables in the 141 * name of making them unusable for userspace. To execute 142 * code at such a low address, the poison must be cleared. 143 * 144 * Note: 'pgd' actually gets set in p4d_alloc() _or_ 145 * pud_alloc() depending on 4/5-level paging. 146 */ 147 pgd->pgd &= ~_PAGE_NX; 148 149 return 0; 150 } 151 152 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, 153 unsigned long nr) 154 { 155 /* Reuse the original kernel mapping */ 156 tboot_pg_dir = pgd_alloc(&tboot_mm); 157 if (!tboot_pg_dir) 158 return -1; 159 160 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { 161 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) 162 return -1; 163 } 164 165 return 0; 166 } 167 168 static void tboot_create_trampoline(void) 169 { 170 u32 map_base, map_size; 171 172 /* Create identity map for tboot shutdown code. */ 173 map_base = PFN_DOWN(tboot->tboot_base); 174 map_size = PFN_UP(tboot->tboot_size); 175 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) 176 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", 177 map_base, map_size); 178 } 179 180 #ifdef CONFIG_ACPI_SLEEP 181 182 static void add_mac_region(phys_addr_t start, unsigned long size) 183 { 184 struct tboot_mac_region *mr; 185 phys_addr_t end = start + size; 186 187 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) 188 panic("tboot: Too many MAC regions\n"); 189 190 if (start && size) { 191 mr = &tboot->mac_regions[tboot->num_mac_regions++]; 192 mr->start = round_down(start, PAGE_SIZE); 193 mr->size = round_up(end, PAGE_SIZE) - mr->start; 194 } 195 } 196 197 static int tboot_setup_sleep(void) 198 { 199 int i; 200 201 tboot->num_mac_regions = 0; 202 203 for (i = 0; i < e820_table->nr_entries; i++) { 204 if ((e820_table->entries[i].type != E820_TYPE_RAM) 205 && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) 206 continue; 207 208 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); 209 } 210 211 tboot->acpi_sinfo.kernel_s3_resume_vector = 212 real_mode_header->wakeup_start; 213 214 return 0; 215 } 216 217 #else /* no CONFIG_ACPI_SLEEP */ 218 219 static int tboot_setup_sleep(void) 220 { 221 /* S3 shutdown requested, but S3 not supported by the kernel... */ 222 BUG(); 223 return -1; 224 } 225 226 #endif 227 228 void tboot_shutdown(u32 shutdown_type) 229 { 230 void (*shutdown)(void); 231 232 if (!tboot_enabled()) 233 return; 234 235 /* 236 * if we're being called before the 1:1 mapping is set up then just 237 * return and let the normal shutdown happen; this should only be 238 * due to very early panic() 239 */ 240 if (!tboot_pg_dir) 241 return; 242 243 /* if this is S3 then set regions to MAC */ 244 if (shutdown_type == TB_SHUTDOWN_S3) 245 if (tboot_setup_sleep()) 246 return; 247 248 tboot->shutdown_type = shutdown_type; 249 250 switch_to_tboot_pt(); 251 252 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 253 shutdown(); 254 255 /* should not reach here */ 256 while (1) 257 halt(); 258 } 259 260 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 261 { 262 #define TB_COPY_GAS(tbg, g) \ 263 tbg.space_id = g.space_id; \ 264 tbg.bit_width = g.bit_width; \ 265 tbg.bit_offset = g.bit_offset; \ 266 tbg.access_width = g.access_width; \ 267 tbg.address = g.address; 268 269 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 270 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 271 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 272 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 273 274 /* 275 * We need phys addr of waking vector, but can't use virt_to_phys() on 276 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 277 * addr. 278 */ 279 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 280 offsetof(struct acpi_table_facs, firmware_waking_vector); 281 } 282 283 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 284 { 285 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 286 /* S0,1,2: */ -1, -1, -1, 287 /* S3: */ TB_SHUTDOWN_S3, 288 /* S4: */ TB_SHUTDOWN_S4, 289 /* S5: */ TB_SHUTDOWN_S5 }; 290 291 if (!tboot_enabled()) 292 return 0; 293 294 tboot_copy_fadt(&acpi_gbl_FADT); 295 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 296 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 297 /* we always use the 32b wakeup vector */ 298 tboot->acpi_sinfo.vector_width = 32; 299 300 if (sleep_state >= ACPI_S_STATE_COUNT || 301 acpi_shutdown_map[sleep_state] == -1) { 302 pr_warn("unsupported sleep state 0x%x\n", sleep_state); 303 return -1; 304 } 305 306 tboot_shutdown(acpi_shutdown_map[sleep_state]); 307 return 0; 308 } 309 310 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) 311 { 312 if (!tboot_enabled()) 313 return 0; 314 315 pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); 316 return -ENODEV; 317 } 318 319 static atomic_t ap_wfs_count; 320 321 static int tboot_wait_for_aps(int num_aps) 322 { 323 unsigned long timeout; 324 325 timeout = AP_WAIT_TIMEOUT*HZ; 326 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 327 timeout) { 328 mdelay(1); 329 timeout--; 330 } 331 332 if (timeout) 333 pr_warn("tboot wait for APs timeout\n"); 334 335 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 336 } 337 338 static int tboot_dying_cpu(unsigned int cpu) 339 { 340 atomic_inc(&ap_wfs_count); 341 if (num_online_cpus() == 1) { 342 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) 343 return -EBUSY; 344 } 345 return 0; 346 } 347 348 #ifdef CONFIG_DEBUG_FS 349 350 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 351 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } 352 353 #define TBOOT_SERIAL_LOG_ADDR 0x60000 354 #define TBOOT_SERIAL_LOG_SIZE 0x08000 355 #define LOG_MAX_SIZE_OFF 16 356 #define LOG_BUF_OFF 24 357 358 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; 359 360 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) 361 { 362 void __iomem *log_base; 363 u8 log_uuid[16]; 364 u32 max_size; 365 void *kbuf; 366 int ret = -EFAULT; 367 368 log_base = ioremap(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); 369 if (!log_base) 370 return ret; 371 372 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); 373 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) 374 goto err_iounmap; 375 376 max_size = readl(log_base + LOG_MAX_SIZE_OFF); 377 if (*ppos >= max_size) { 378 ret = 0; 379 goto err_iounmap; 380 } 381 382 if (*ppos + count > max_size) 383 count = max_size - *ppos; 384 385 kbuf = kmalloc(count, GFP_KERNEL); 386 if (!kbuf) { 387 ret = -ENOMEM; 388 goto err_iounmap; 389 } 390 391 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); 392 if (copy_to_user(user_buf, kbuf, count)) 393 goto err_kfree; 394 395 *ppos += count; 396 397 ret = count; 398 399 err_kfree: 400 kfree(kbuf); 401 402 err_iounmap: 403 iounmap(log_base); 404 405 return ret; 406 } 407 408 static const struct file_operations tboot_log_fops = { 409 .read = tboot_log_read, 410 .llseek = default_llseek, 411 }; 412 413 #endif /* CONFIG_DEBUG_FS */ 414 415 static __init int tboot_late_init(void) 416 { 417 if (!tboot_enabled()) 418 return 0; 419 420 tboot_create_trampoline(); 421 422 atomic_set(&ap_wfs_count, 0); 423 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, 424 tboot_dying_cpu); 425 #ifdef CONFIG_DEBUG_FS 426 debugfs_create_file("tboot_log", S_IRUSR, 427 arch_debugfs_dir, NULL, &tboot_log_fops); 428 #endif 429 430 acpi_os_set_prepare_sleep(&tboot_sleep); 431 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); 432 return 0; 433 } 434 435 late_initcall(tboot_late_init); 436 437 /* 438 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 439 */ 440 441 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 442 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 443 444 /* # pages for each config regs space - used by fixmap */ 445 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 446 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 447 448 /* offsets from pub/priv config space */ 449 #define TXTCR_HEAP_BASE 0x0300 450 #define TXTCR_HEAP_SIZE 0x0308 451 452 #define SHA1_SIZE 20 453 454 struct sha1_hash { 455 u8 hash[SHA1_SIZE]; 456 }; 457 458 struct sinit_mle_data { 459 u32 version; /* currently 6 */ 460 struct sha1_hash bios_acm_id; 461 u32 edx_senter_flags; 462 u64 mseg_valid; 463 struct sha1_hash sinit_hash; 464 struct sha1_hash mle_hash; 465 struct sha1_hash stm_hash; 466 struct sha1_hash lcp_policy_hash; 467 u32 lcp_policy_control; 468 u32 rlp_wakeup_addr; 469 u32 reserved; 470 u32 num_mdrs; 471 u32 mdrs_off; 472 u32 num_vtd_dmars; 473 u32 vtd_dmars_off; 474 } __packed; 475 476 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 477 { 478 void *heap_base, *heap_ptr, *config; 479 480 if (!tboot_enabled()) 481 return dmar_tbl; 482 483 /* 484 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 485 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 486 */ 487 488 /* map config space in order to get heap addr */ 489 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 490 PAGE_SIZE); 491 if (!config) 492 return NULL; 493 494 /* now map TXT heap */ 495 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 496 *(u64 *)(config + TXTCR_HEAP_SIZE)); 497 iounmap(config); 498 if (!heap_base) 499 return NULL; 500 501 /* walk heap to SinitMleData */ 502 /* skip BiosData */ 503 heap_ptr = heap_base + *(u64 *)heap_base; 504 /* skip OsMleData */ 505 heap_ptr += *(u64 *)heap_ptr; 506 /* skip OsSinitData */ 507 heap_ptr += *(u64 *)heap_ptr; 508 /* now points to SinitMleDataSize; set to SinitMleData */ 509 heap_ptr += sizeof(u64); 510 /* get addr of DMAR table */ 511 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 512 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 513 sizeof(u64)); 514 515 /* don't unmap heap because dmar.c needs access to this */ 516 517 return dmar_tbl; 518 } 519 520 int tboot_force_iommu(void) 521 { 522 if (!tboot_enabled()) 523 return 0; 524 525 if (no_iommu || dmar_disabled) 526 pr_warn("Forcing Intel-IOMMU to enabled\n"); 527 528 dmar_disabled = 0; 529 no_iommu = 0; 530 531 return 1; 532 } 533