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
tboot_enabled(void)47 bool tboot_enabled(void)
48 {
49 return tboot != NULL;
50 }
51
tboot_probe(void)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
switch_to_tboot_pt(void)102 static inline void switch_to_tboot_pt(void)
103 {
104 write_cr3(virt_to_phys(tboot_pg_dir));
105 }
106
map_tboot_page(unsigned long vaddr,unsigned long pfn,pgprot_t prot)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
map_tboot_pages(unsigned long vaddr,unsigned long start_pfn,unsigned long nr)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
tboot_create_trampoline(void)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
add_mac_region(phys_addr_t start,unsigned long size)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
tboot_setup_sleep(void)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
tboot_setup_sleep(void)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
tboot_shutdown(u32 shutdown_type)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
tboot_copy_fadt(const struct acpi_table_fadt * fadt)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
tboot_sleep(u8 sleep_state,u32 pm1a_control,u32 pm1b_control)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
tboot_extended_sleep(u8 sleep_state,u32 val_a,u32 val_b)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
tboot_wait_for_aps(int num_aps)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
tboot_dying_cpu(unsigned int cpu)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
tboot_log_read(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)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
tboot_late_init(void)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
tboot_get_dmar_table(struct acpi_table_header * dmar_tbl)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
tboot_force_iommu(void)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