// SPDX-License-Identifier: GPL-2.0-only /* * tboot.c: main implementation of helper functions used by kernel for * runtime support of Intel(R) Trusted Execution Technology * * Copyright (c) 2006-2009, Intel Corporation */ #include <linux/intel-iommu.h> #include <linux/init_task.h> #include <linux/spinlock.h> #include <linux/export.h> #include <linux/delay.h> #include <linux/sched.h> #include <linux/init.h> #include <linux/dmar.h> #include <linux/cpu.h> #include <linux/pfn.h> #include <linux/mm.h> #include <linux/tboot.h> #include <linux/debugfs.h> #include <asm/realmode.h> #include <asm/processor.h> #include <asm/bootparam.h> #include <asm/pgtable.h> #include <asm/pgalloc.h> #include <asm/swiotlb.h> #include <asm/fixmap.h> #include <asm/proto.h> #include <asm/setup.h> #include <asm/e820/api.h> #include <asm/io.h> #include "../realmode/rm/wakeup.h" /* Global pointer to shared data; NULL means no measured launch. */ struct tboot *tboot __read_mostly; EXPORT_SYMBOL(tboot); /* timeout for APs (in secs) to enter wait-for-SIPI state during shutdown */ #define AP_WAIT_TIMEOUT 1 #undef pr_fmt #define pr_fmt(fmt) "tboot: " fmt static u8 tboot_uuid[16] __initdata = TBOOT_UUID; void __init tboot_probe(void) { /* Look for valid page-aligned address for shared page. */ if (!boot_params.tboot_addr) return; /* * also verify that it is mapped as we expect it before calling * set_fixmap(), to reduce chance of garbage value causing crash */ if (!e820__mapped_any(boot_params.tboot_addr, boot_params.tboot_addr, E820_TYPE_RESERVED)) { pr_warning("non-0 tboot_addr but it is not of type E820_TYPE_RESERVED\n"); return; } /* Map and check for tboot UUID. */ set_fixmap(FIX_TBOOT_BASE, boot_params.tboot_addr); tboot = (struct tboot *)fix_to_virt(FIX_TBOOT_BASE); if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) { pr_warning("tboot at 0x%llx is invalid\n", boot_params.tboot_addr); tboot = NULL; return; } if (tboot->version < 5) { pr_warning("tboot version is invalid: %u\n", tboot->version); tboot = NULL; return; } pr_info("found shared page at phys addr 0x%llx:\n", boot_params.tboot_addr); pr_debug("version: %d\n", tboot->version); pr_debug("log_addr: 0x%08x\n", tboot->log_addr); pr_debug("shutdown_entry: 0x%x\n", tboot->shutdown_entry); pr_debug("tboot_base: 0x%08x\n", tboot->tboot_base); pr_debug("tboot_size: 0x%x\n", tboot->tboot_size); } static pgd_t *tboot_pg_dir; static struct mm_struct tboot_mm = { .mm_rb = RB_ROOT, .pgd = swapper_pg_dir, .mm_users = ATOMIC_INIT(2), .mm_count = ATOMIC_INIT(1), .mmap_sem = __RWSEM_INITIALIZER(init_mm.mmap_sem), .page_table_lock = __SPIN_LOCK_UNLOCKED(init_mm.page_table_lock), .mmlist = LIST_HEAD_INIT(init_mm.mmlist), }; static inline void switch_to_tboot_pt(void) { write_cr3(virt_to_phys(tboot_pg_dir)); } static int map_tboot_page(unsigned long vaddr, unsigned long pfn, pgprot_t prot) { pgd_t *pgd; p4d_t *p4d; pud_t *pud; pmd_t *pmd; pte_t *pte; pgd = pgd_offset(&tboot_mm, vaddr); p4d = p4d_alloc(&tboot_mm, pgd, vaddr); if (!p4d) return -1; pud = pud_alloc(&tboot_mm, p4d, vaddr); if (!pud) return -1; pmd = pmd_alloc(&tboot_mm, pud, vaddr); if (!pmd) return -1; pte = pte_alloc_map(&tboot_mm, pmd, vaddr); if (!pte) return -1; set_pte_at(&tboot_mm, vaddr, pte, pfn_pte(pfn, prot)); pte_unmap(pte); /* * PTI poisons low addresses in the kernel page tables in the * name of making them unusable for userspace. To execute * code at such a low address, the poison must be cleared. * * Note: 'pgd' actually gets set in p4d_alloc() _or_ * pud_alloc() depending on 4/5-level paging. */ pgd->pgd &= ~_PAGE_NX; return 0; } static int map_tboot_pages(unsigned long vaddr, unsigned long start_pfn, unsigned long nr) { /* Reuse the original kernel mapping */ tboot_pg_dir = pgd_alloc(&tboot_mm); if (!tboot_pg_dir) return -1; for (; nr > 0; nr--, vaddr += PAGE_SIZE, start_pfn++) { if (map_tboot_page(vaddr, start_pfn, PAGE_KERNEL_EXEC)) return -1; } return 0; } static void tboot_create_trampoline(void) { u32 map_base, map_size; /* Create identity map for tboot shutdown code. */ map_base = PFN_DOWN(tboot->tboot_base); map_size = PFN_UP(tboot->tboot_size); if (map_tboot_pages(map_base << PAGE_SHIFT, map_base, map_size)) panic("tboot: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", map_base, map_size); } #ifdef CONFIG_ACPI_SLEEP static void add_mac_region(phys_addr_t start, unsigned long size) { struct tboot_mac_region *mr; phys_addr_t end = start + size; if (tboot->num_mac_regions >= MAX_TB_MAC_REGIONS) panic("tboot: Too many MAC regions\n"); if (start && size) { mr = &tboot->mac_regions[tboot->num_mac_regions++]; mr->start = round_down(start, PAGE_SIZE); mr->size = round_up(end, PAGE_SIZE) - mr->start; } } static int tboot_setup_sleep(void) { int i; tboot->num_mac_regions = 0; for (i = 0; i < e820_table->nr_entries; i++) { if ((e820_table->entries[i].type != E820_TYPE_RAM) && (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN)) continue; add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size); } tboot->acpi_sinfo.kernel_s3_resume_vector = real_mode_header->wakeup_start; return 0; } #else /* no CONFIG_ACPI_SLEEP */ static int tboot_setup_sleep(void) { /* S3 shutdown requested, but S3 not supported by the kernel... */ BUG(); return -1; } #endif void tboot_shutdown(u32 shutdown_type) { void (*shutdown)(void); if (!tboot_enabled()) return; /* * if we're being called before the 1:1 mapping is set up then just * return and let the normal shutdown happen; this should only be * due to very early panic() */ if (!tboot_pg_dir) return; /* if this is S3 then set regions to MAC */ if (shutdown_type == TB_SHUTDOWN_S3) if (tboot_setup_sleep()) return; tboot->shutdown_type = shutdown_type; switch_to_tboot_pt(); shutdown = (void(*)(void))(unsigned long)tboot->shutdown_entry; shutdown(); /* should not reach here */ while (1) halt(); } static void tboot_copy_fadt(const struct acpi_table_fadt *fadt) { #define TB_COPY_GAS(tbg, g) \ tbg.space_id = g.space_id; \ tbg.bit_width = g.bit_width; \ tbg.bit_offset = g.bit_offset; \ tbg.access_width = g.access_width; \ tbg.address = g.address; TB_COPY_GAS(tboot->acpi_sinfo.pm1a_cnt_blk, fadt->xpm1a_control_block); TB_COPY_GAS(tboot->acpi_sinfo.pm1b_cnt_blk, fadt->xpm1b_control_block); TB_COPY_GAS(tboot->acpi_sinfo.pm1a_evt_blk, fadt->xpm1a_event_block); TB_COPY_GAS(tboot->acpi_sinfo.pm1b_evt_blk, fadt->xpm1b_event_block); /* * We need phys addr of waking vector, but can't use virt_to_phys() on * &acpi_gbl_FACS because it is ioremap'ed, so calc from FACS phys * addr. */ tboot->acpi_sinfo.wakeup_vector = fadt->facs + offsetof(struct acpi_table_facs, firmware_waking_vector); } static int tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control) { static u32 acpi_shutdown_map[ACPI_S_STATE_COUNT] = { /* S0,1,2: */ -1, -1, -1, /* S3: */ TB_SHUTDOWN_S3, /* S4: */ TB_SHUTDOWN_S4, /* S5: */ TB_SHUTDOWN_S5 }; if (!tboot_enabled()) return 0; tboot_copy_fadt(&acpi_gbl_FADT); tboot->acpi_sinfo.pm1a_cnt_val = pm1a_control; tboot->acpi_sinfo.pm1b_cnt_val = pm1b_control; /* we always use the 32b wakeup vector */ tboot->acpi_sinfo.vector_width = 32; if (sleep_state >= ACPI_S_STATE_COUNT || acpi_shutdown_map[sleep_state] == -1) { pr_warning("unsupported sleep state 0x%x\n", sleep_state); return -1; } tboot_shutdown(acpi_shutdown_map[sleep_state]); return 0; } static int tboot_extended_sleep(u8 sleep_state, u32 val_a, u32 val_b) { if (!tboot_enabled()) return 0; pr_warning("tboot is not able to suspend on platforms with reduced hardware sleep (ACPIv5)"); return -ENODEV; } static atomic_t ap_wfs_count; static int tboot_wait_for_aps(int num_aps) { unsigned long timeout; timeout = AP_WAIT_TIMEOUT*HZ; while (atomic_read((atomic_t *)&tboot->num_in_wfs) != num_aps && timeout) { mdelay(1); timeout--; } if (timeout) pr_warning("tboot wait for APs timeout\n"); return !(atomic_read((atomic_t *)&tboot->num_in_wfs) == num_aps); } static int tboot_dying_cpu(unsigned int cpu) { atomic_inc(&ap_wfs_count); if (num_online_cpus() == 1) { if (tboot_wait_for_aps(atomic_read(&ap_wfs_count))) return -EBUSY; } return 0; } #ifdef CONFIG_DEBUG_FS #define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \ 0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 } #define TBOOT_SERIAL_LOG_ADDR 0x60000 #define TBOOT_SERIAL_LOG_SIZE 0x08000 #define LOG_MAX_SIZE_OFF 16 #define LOG_BUF_OFF 24 static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID; static ssize_t tboot_log_read(struct file *file, char __user *user_buf, size_t count, loff_t *ppos) { void __iomem *log_base; u8 log_uuid[16]; u32 max_size; void *kbuf; int ret = -EFAULT; log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE); if (!log_base) return ret; memcpy_fromio(log_uuid, log_base, sizeof(log_uuid)); if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid))) goto err_iounmap; max_size = readl(log_base + LOG_MAX_SIZE_OFF); if (*ppos >= max_size) { ret = 0; goto err_iounmap; } if (*ppos + count > max_size) count = max_size - *ppos; kbuf = kmalloc(count, GFP_KERNEL); if (!kbuf) { ret = -ENOMEM; goto err_iounmap; } memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count); if (copy_to_user(user_buf, kbuf, count)) goto err_kfree; *ppos += count; ret = count; err_kfree: kfree(kbuf); err_iounmap: iounmap(log_base); return ret; } static const struct file_operations tboot_log_fops = { .read = tboot_log_read, .llseek = default_llseek, }; #endif /* CONFIG_DEBUG_FS */ static __init int tboot_late_init(void) { if (!tboot_enabled()) return 0; tboot_create_trampoline(); atomic_set(&ap_wfs_count, 0); cpuhp_setup_state(CPUHP_AP_X86_TBOOT_DYING, "x86/tboot:dying", NULL, tboot_dying_cpu); #ifdef CONFIG_DEBUG_FS debugfs_create_file("tboot_log", S_IRUSR, arch_debugfs_dir, NULL, &tboot_log_fops); #endif acpi_os_set_prepare_sleep(&tboot_sleep); acpi_os_set_prepare_extended_sleep(&tboot_extended_sleep); return 0; } late_initcall(tboot_late_init); /* * TXT configuration registers (offsets from TXT_{PUB, PRIV}_CONFIG_REGS_BASE) */ #define TXT_PUB_CONFIG_REGS_BASE 0xfed30000 #define TXT_PRIV_CONFIG_REGS_BASE 0xfed20000 /* # pages for each config regs space - used by fixmap */ #define NR_TXT_CONFIG_PAGES ((TXT_PUB_CONFIG_REGS_BASE - \ TXT_PRIV_CONFIG_REGS_BASE) >> PAGE_SHIFT) /* offsets from pub/priv config space */ #define TXTCR_HEAP_BASE 0x0300 #define TXTCR_HEAP_SIZE 0x0308 #define SHA1_SIZE 20 struct sha1_hash { u8 hash[SHA1_SIZE]; }; struct sinit_mle_data { u32 version; /* currently 6 */ struct sha1_hash bios_acm_id; u32 edx_senter_flags; u64 mseg_valid; struct sha1_hash sinit_hash; struct sha1_hash mle_hash; struct sha1_hash stm_hash; struct sha1_hash lcp_policy_hash; u32 lcp_policy_control; u32 rlp_wakeup_addr; u32 reserved; u32 num_mdrs; u32 mdrs_off; u32 num_vtd_dmars; u32 vtd_dmars_off; } __packed; struct acpi_table_header *tboot_get_dmar_table(struct acpi_table_header *dmar_tbl) { void *heap_base, *heap_ptr, *config; if (!tboot_enabled()) return dmar_tbl; /* * ACPI tables may not be DMA protected by tboot, so use DMAR copy * SINIT saved in SinitMleData in TXT heap (which is DMA protected) */ /* map config space in order to get heap addr */ config = ioremap(TXT_PUB_CONFIG_REGS_BASE, NR_TXT_CONFIG_PAGES * PAGE_SIZE); if (!config) return NULL; /* now map TXT heap */ heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE), *(u64 *)(config + TXTCR_HEAP_SIZE)); iounmap(config); if (!heap_base) return NULL; /* walk heap to SinitMleData */ /* skip BiosData */ heap_ptr = heap_base + *(u64 *)heap_base; /* skip OsMleData */ heap_ptr += *(u64 *)heap_ptr; /* skip OsSinitData */ heap_ptr += *(u64 *)heap_ptr; /* now points to SinitMleDataSize; set to SinitMleData */ heap_ptr += sizeof(u64); /* get addr of DMAR table */ dmar_tbl = (struct acpi_table_header *)(heap_ptr + ((struct sinit_mle_data *)heap_ptr)->vtd_dmars_off - sizeof(u64)); /* don't unmap heap because dmar.c needs access to this */ return dmar_tbl; } int tboot_force_iommu(void) { if (!tboot_enabled()) return 0; if (intel_iommu_tboot_noforce) return 1; if (no_iommu || swiotlb || dmar_disabled) pr_warning("Forcing Intel-IOMMU to enabled\n"); dmar_disabled = 0; #ifdef CONFIG_SWIOTLB swiotlb = 0; #endif no_iommu = 0; return 1; }