tboot.c 13 KB

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