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/swiotlb.h> 28 #include <asm/fixmap.h> 29 #include <asm/proto.h> 30 #include <asm/setup.h> 31 #include <asm/e820/api.h> 32 #include <asm/io.h> 33 34 #include "../realmode/rm/wakeup.h" 35 36 /* Global pointer to shared data; NULL means no measured launch. */ 37 static struct tboot *tboot __read_mostly; 38 39 /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ 40 #define AP_WAIT_TIMEOUT 1 41 42 #undef pr_fmt 43 #define pr_fmt(fmt) "tboot: " fmt 44 45 static u8 tboot_uuid[16] __initdata = TBOOT_UUID; 46 47 bool tboot_enabled(void) 48 { 49 return tboot != NULL; 50 } 51 52 /* noinline to prevent gcc from warning about dereferencing constant fixaddr */ 53 static noinline __init bool check_tboot_version(void) 54 { 55 if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { 56 pr_warn("tboot at 0x%llx is invalid\n", boot_params.tboot_addr); 57 return false; 58 } 59 60 if (tboot->version < 5) { 61 pr_warn("tboot version is invalid: %u\n", tboot->version); 62 return false; 63 } 64 65 pr_info("found shared page at phys addr 0x%llx:\n", 66 boot_params.tboot_addr); 67 pr_debug("version: %d\n", tboot->version); 68 pr_debug("log_addr: 0x%08x\n", tboot->log_addr); 69 pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); 70 pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); 71 pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); 72 73 return true; 74 } 75 76 void __init tboot_probe(void) 77 { 78 /* Look for valid page-aligned address for shared page. */ 79 if (!boot_params.tboot_addr) 80 return; 81 /* 82 * also verify that it is mapped as we expect it before calling 83 * set_fixmap(), to reduce chance of garbage value causing crash 84 */ 85 if (!e820__mapped_any(boot_params.tboot_addr, 86 boot_params.tboot_addr, E820_TYPE_RESERVED)) { 87 pr_warn("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n"); 88 return; 89 } 90 91 /* Map and check for tboot UUID. */ 92 set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); 93 tboot = (void *)fix_to_virt(FIX_TBOOT_BASE); 94 if (!check_tboot_version()) 95 tboot = NULL; 96 } 97 98 static pgd_t *tboot_pg_dir; 99 static struct mm_struct tboot_mm = { 100 .mm_rb = RB_ROOT, 101 .pgd = swapper_pg_dir, 102 .mm_users = ATOMIC_INIT(2), 103 .mm_count = ATOMIC_INIT(1), 104 .write_protect_seq = SEQCNT_ZERO(tboot_mm.write_protect_seq), 105 MMAP_LOCK_INITIALIZER(init_mm) 106 .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), 107 .mmlist = LIST_HEAD_INIT(init_mm.mmlist), 108 }; 109 110 static inline void switch_to_tboot_pt(void) 111 { 112 write_cr3(virt_to_phys(tboot_pg_dir)); 113 } 114 115 static int map_tboot_page(unsigned long vaddr, unsigned long pfn, 116 pgprot_t prot) 117 { 118 pgd_t *pgd; 119 p4d_t *p4d; 120 pud_t *pud; 121 pmd_t *pmd; 122 pte_t *pte; 123 124 pgd = pgd_offset(&tboot_mm, vaddr); 125 p4d = p4d_alloc(&tboot_mm, pgd, vaddr); 126 if (!p4d) 127 return -1; 128 pud = pud_alloc(&tboot_mm, p4d, vaddr); 129 if (!pud) 130 return -1; 131 pmd = pmd_alloc(&tboot_mm, pud, vaddr); 132 if (!pmd) 133 return -1; 134 pte = pte_alloc_map(&tboot_mm, pmd, vaddr); 135 if (!pte) 136 return -1; 137 set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); 138 pte_unmap(pte); 139 140 /* 141 * PTI poisons low addresses in the kernel page tables in the 142 * name of making them unusable for userspace. To execute 143 * code at such a low address, the poison must be cleared. 144 * 145 * Note: 'pgd' actually gets set in p4d_alloc() _or_ 146 * pud_alloc() depending on 4/5-level paging. 147 */ 148 pgd->pgd &= ~_PAGE_NX; 149 150 return 0; 151 } 152 153 static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, 154 unsigned long nr) 155 { 156 /* Reuse the original kernel mapping */ 157 tboot_pg_dir = pgd_alloc(&tboot_mm); 158 if (!tboot_pg_dir) 159 return -1; 160 161 for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { 162 if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) 163 return -1; 164 } 165 166 return 0; 167 } 168 169 static void tboot_create_trampoline(void) 170 { 171 u32 map_base, map_size; 172 173 /* Create identity map for tboot shutdown code. */ 174 map_base = PFN_DOWN(tboot->tboot_base); 175 map_size = PFN_UP(tboot->tboot_size); 176 if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) 177 panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", 178 map_base, map_size); 179 } 180 181 #ifdef CONFIG_ACPI_SLEEP 182 183 static void add_mac_region(phys_addr_t start, unsigned long size) 184 { 185 struct tboot_mac_region *mr; 186 phys_addr_t end = start + size; 187 188 if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) 189 panic("tboot: Too many MAC regions\n"); 190 191 if (start && size) { 192 mr = &tboot->mac_regions[tboot->num_mac_regions++]; 193 mr->start = round_down(start, PAGE_SIZE); 194 mr->size = round_up(end, PAGE_SIZE) - mr->start; 195 } 196 } 197 198 static int tboot_setup_sleep(void) 199 { 200 int i; 201 202 tboot->num_mac_regions = 0; 203 204 for (i = 0; i < e820_table->nr_entries; i++) { 205 if ((e820_table->entries[i].type != E820_TYPE_RAM) 206 && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) 207 continue; 208 209 add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); 210 } 211 212 tboot->acpi_sinfo.kernel_s3_resume_vector = 213 real_mode_header->wakeup_start; 214 215 return 0; 216 } 217 218 #else /* no CONFIG_ACPI_SLEEP */ 219 220 static int tboot_setup_sleep(void) 221 { 222 /* S3 shutdown requested, but S3 not supported by the kernel... */ 223 BUG(); 224 return -1; 225 } 226 227 #endif 228 229 void tboot_shutdown(u32 shutdown_type) 230 { 231 void (*shutdown)(void); 232 233 if (!tboot_enabled()) 234 return; 235 236 /* 237 * if we're being called before the 1:1 mapping is set up then just 238 * return and let the normal shutdown happen; this should only be 239 * due to very early panic() 240 */ 241 if (!tboot_pg_dir) 242 return; 243 244 /* if this is S3 then set regions to MAC */ 245 if (shutdown_type == TB_SHUTDOWN_S3) 246 if (tboot_setup_sleep()) 247 return; 248 249 tboot->shutdown_type = shutdown_type; 250 251 switch_to_tboot_pt(); 252 253 shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; 254 shutdown(); 255 256 /* should not reach here */ 257 while (1) 258 halt(); 259 } 260 261 static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) 262 { 263 #define TB_COPY_GAS(tbg, g) \ 264 tbg.space_id = g.space_id; \ 265 tbg.bit_width = g.bit_width; \ 266 tbg.bit_offset = g.bit_offset; \ 267 tbg.access_width = g.access_width; \ 268 tbg.address = g.address; 269 270 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); 271 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); 272 TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); 273 TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); 274 275 /* 276 * We need phys addr of waking vector, but can't use virt_to_phys() on 277 * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys 278 * addr. 279 */ 280 tboot->acpi_sinfo.wakeup_vector = fadt->facs + 281 offsetof(struct acpi_table_facs, firmware_waking_vector); 282 } 283 284 static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) 285 { 286 static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { 287 /* S0,1,2: */ -1, -1, -1, 288 /* S3: */ TB_SHUTDOWN_S3, 289 /* S4: */ TB_SHUTDOWN_S4, 290 /* S5: */ TB_SHUTDOWN_S5 }; 291 292 if (!tboot_enabled()) 293 return 0; 294 295 tboot_copy_fadt(&acpi_gbl_FADT); 296 tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; 297 tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; 298 /* we always use the 32b wakeup vector */ 299 tboot->acpi_sinfo.vector_width = 32; 300 301 if (sleep_state >= ACPI_S_STATE_COUNT || 302 acpi_shutdown_map[sleep_state] == -1) { 303 pr_warn("unsupported sleep state 0x%x\n", sleep_state); 304 return -1; 305 } 306 307 tboot_shutdown(acpi_shutdown_map[sleep_state]); 308 return 0; 309 } 310 311 static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) 312 { 313 if (!tboot_enabled()) 314 return 0; 315 316 pr_warn("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); 317 return -ENODEV; 318 } 319 320 static atomic_t ap_wfs_count; 321 322 static int tboot_wait_for_aps(int num_aps) 323 { 324 unsigned long timeout; 325 326 timeout = AP_WAIT_TIMEOUT*HZ; 327 while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && 328 timeout) { 329 mdelay(1); 330 timeout--; 331 } 332 333 if (timeout) 334 pr_warn("tboot wait for APs timeout\n"); 335 336 return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); 337 } 338 339 static int tboot_dying_cpu(unsigned int cpu) 340 { 341 atomic_inc(&ap_wfs_count); 342 if (num_online_cpus() == 1) { 343 if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) 344 return -EBUSY; 345 } 346 return 0; 347 } 348 349 #ifdef CONFIG_DEBUG_FS 350 351 #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 352 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } 353 354 #define TBOOT_SERIAL_LOG_ADDR 0x60000 355 #define TBOOT_SERIAL_LOG_SIZE 0x08000 356 #define LOG_MAX_SIZE_OFF 16 357 #define LOG_BUF_OFF 24 358 359 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; 360 361 static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) 362 { 363 void __iomem *log_base; 364 u8 log_uuid[16]; 365 u32 max_size; 366 void *kbuf; 367 int ret = -EFAULT; 368 369 log_base = ioremap(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); 370 if (!log_base) 371 return ret; 372 373 memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); 374 if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) 375 goto err_iounmap; 376 377 max_size = readl(log_base + LOG_MAX_SIZE_OFF); 378 if (*ppos >= max_size) { 379 ret = 0; 380 goto err_iounmap; 381 } 382 383 if (*ppos + count > max_size) 384 count = max_size - *ppos; 385 386 kbuf = kmalloc(count, GFP_KERNEL); 387 if (!kbuf) { 388 ret = -ENOMEM; 389 goto err_iounmap; 390 } 391 392 memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); 393 if (copy_to_user(user_buf, kbuf, count)) 394 goto err_kfree; 395 396 *ppos += count; 397 398 ret = count; 399 400 err_kfree: 401 kfree(kbuf); 402 403 err_iounmap: 404 iounmap(log_base); 405 406 return ret; 407 } 408 409 static const struct file_operations tboot_log_fops = { 410 .read = tboot_log_read, 411 .llseek = default_llseek, 412 }; 413 414 #endif /* CONFIG_DEBUG_FS */ 415 416 static __init int tboot_late_init(void) 417 { 418 if (!tboot_enabled()) 419 return 0; 420 421 tboot_create_trampoline(); 422 423 atomic_set(&ap_wfs_count, 0); 424 cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, 425 tboot_dying_cpu); 426 #ifdef CONFIG_DEBUG_FS 427 debugfs_create_file("tboot_log", S_IRUSR, 428 arch_debugfs_dir, NULL, &tboot_log_fops); 429 #endif 430 431 acpi_os_set_prepare_sleep(&tboot_sleep); 432 acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); 433 return 0; 434 } 435 436 late_initcall(tboot_late_init); 437 438 /* 439 * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) 440 */ 441 442 #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 443 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 444 445 /* # pages for each config regs space - used by fixmap */ 446 #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ 447 TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) 448 449 /* offsets from pub/priv config space */ 450 #define TXTCR_HEAP_BASE 0x0300 451 #define TXTCR_HEAP_SIZE 0x0308 452 453 #define SHA1_SIZE 20 454 455 struct sha1_hash { 456 u8 hash[SHA1_SIZE]; 457 }; 458 459 struct sinit_mle_data { 460 u32 version; /* currently 6 */ 461 struct sha1_hash bios_acm_id; 462 u32 edx_senter_flags; 463 u64 mseg_valid; 464 struct sha1_hash sinit_hash; 465 struct sha1_hash mle_hash; 466 struct sha1_hash stm_hash; 467 struct sha1_hash lcp_policy_hash; 468 u32 lcp_policy_control; 469 u32 rlp_wakeup_addr; 470 u32 reserved; 471 u32 num_mdrs; 472 u32 mdrs_off; 473 u32 num_vtd_dmars; 474 u32 vtd_dmars_off; 475 } __packed; 476 477 struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) 478 { 479 void *heap_base, *heap_ptr, *config; 480 481 if (!tboot_enabled()) 482 return dmar_tbl; 483 484 /* 485 * ACPI tables may not be DMA protected by tboot, so use DMAR copy 486 * SINIT saved in SinitMleData in TXT heap (which is DMA protected) 487 */ 488 489 /* map config space in order to get heap addr */ 490 config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * 491 PAGE_SIZE); 492 if (!config) 493 return NULL; 494 495 /* now map TXT heap */ 496 heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), 497 *(u64 *)(config + TXTCR_HEAP_SIZE)); 498 iounmap(config); 499 if (!heap_base) 500 return NULL; 501 502 /* walk heap to SinitMleData */ 503 /* skip BiosData */ 504 heap_ptr = heap_base + *(u64 *)heap_base; 505 /* skip OsMleData */ 506 heap_ptr += *(u64 *)heap_ptr; 507 /* skip OsSinitData */ 508 heap_ptr += *(u64 *)heap_ptr; 509 /* now points to SinitMleDataSize; set to SinitMleData */ 510 heap_ptr += sizeof(u64); 511 /* get addr of DMAR table */ 512 dmar_tbl = (struct acpi_table_header *)(heap_ptr + 513 ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - 514 sizeof(u64)); 515 516 /* don't unmap heap because dmar.c needs access to this */ 517 518 return dmar_tbl; 519 } 520 521 int tboot_force_iommu(void) 522 { 523 if (!tboot_enabled()) 524 return 0; 525 526 if (no_iommu || dmar_disabled) 527 pr_warn("Forcing Intel-IOMMU to enabled\n"); 528 529 dmar_disabled = 0; 530 no_iommu = 0; 531 532 return 1; 533 } 534