summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/tboot.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/tboot.c')
-rw-r--r--arch/x86/kernel/tboot.c517
1 files changed, 517 insertions, 0 deletions
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
new file mode 100644
index 000000000..4c1bcb605
--- /dev/null
+++ b/arch/x86/kernel/tboot.c
@@ -0,0 +1,517 @@
+// 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/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/pgalloc.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. */
+static struct tboot *tboot __read_mostly;
+
+/* 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;
+
+bool tboot_enabled(void)
+{
+ return tboot != NULL;
+}
+
+/* noinline to prevent gcc from warning about dereferencing constant fixaddr */
+static noinline __init bool check_tboot_version(void)
+{
+ if (memcmp(&tboot_uuid, &tboot->uuid, sizeof(tboot->uuid))) {
+ pr_warn("tboot at 0x%llx is invalid\n", boot_params.tboot_addr);
+ return false;
+ }
+
+ if (tboot->version < 5) {
+ pr_warn("tboot version is invalid: %u\n", tboot->version);
+ return false;
+ }
+
+ 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);
+
+ return true;
+}
+
+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_warn("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 = (void *)fix_to_virt(FIX_TBOOT_BASE);
+ if (!check_tboot_version())
+ tboot = NULL;
+}
+
+static pgd_t *tboot_pg_dir;
+static struct mm_struct tboot_mm = {
+ .mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, tboot_mm.mmap_lock),
+ .pgd = swapper_pg_dir,
+ .mm_users = ATOMIC_INIT(2),
+ .mm_count = ATOMIC_INIT(1),
+ .write_protect_seq = SEQCNT_ZERO(tboot_mm.write_protect_seq),
+ MMAP_LOCK_INITIALIZER(init_mm)
+ .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_warn("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_warn("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_warn("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(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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 14:31:41 +0000