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