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