--- /dev/null
+Intel(R) TXT Overview:
+=====================
+
+Intel's technology for safer computing, Intel(R) Trusted Execution
+Technology (Intel(R) TXT), defines platform-level enhancements that
+provide the building blocks for creating trusted platforms.
+
+Intel TXT was formerly known by the code name LaGrande Technology (LT).
+
+Intel TXT in Brief:
+o Provides dynamic root of trust for measurement (DRTM)
+o Data protection in case of improper shutdown
+o Measurement and verification of launched environment
+
+Intel TXT is part of the vPro(TM) brand and is also available some
+non-vPro systems. It is currently available on desktop systems
+based on the Q35, X38, Q45, and Q43 Express chipsets (e.g. Dell
+Optiplex 755, HP dc7800, etc.) and mobile systems based on the GM45,
+PM45, and GS45 Express chipsets.
+
+For more information, see http://www.intel.com/technology/security/.
+This site also has a link to the Intel TXT MLE Developers Manual,
+which has been updated for the new released platforms.
+
+Intel TXT has been presented at various events over the past few
+years, some of which are:
+ LinuxTAG 2008:
+ http://www.linuxtag.org/2008/en/conf/events/vp-donnerstag/
+ details.html?talkid=110
+ TRUST2008:
+ http://www.trust2008.eu/downloads/Keynote-Speakers/
+ 3_David-Grawrock_The-Front-Door-of-Trusted-Computing.pdf
+ IDF 2008, Shanghai:
+ http://inteldeveloperforum.com.edgesuite.net/shanghai_2008/
+ aep/PROS003/index.html
+ IDFs 2006, 2007 (I'm not sure if/where they are online)
+
+Trusted Boot Project Overview:
+=============================
+
+Trusted Boot (tboot) is an open source, pre- kernel/VMM module that
+uses Intel TXT to perform a measured and verified launch of an OS
+kernel/VMM.
+
+It is hosted on SourceForge at http://sourceforge.net/projects/tboot.
+The mercurial source repo is available at http://www.bughost.org/
+repos.hg/tboot.hg.
+
+Tboot currently supports launching Xen (open source VMM/hypervisor
+w/ TXT support since v3.2), and now Linux kernels.
+
+
+Value Proposition for Linux or "Why should you care?"
+=====================================================
+
+While there are many products and technologies that attempt to
+measure or protect the integrity of a running kernel, they all
+assume the kernel is "good" to begin with. The Integrity
+Measurement Architecture (IMA) and Linux Integrity Module interface
+are examples of such solutions.
+
+To get trust in the initial kernel without using Intel TXT, a
+static root of trust must be used. This bases trust in BIOS
+starting at system reset and requires measurement of all code
+executed between system reset through the completion of the kernel
+boot as well as data objects used by that code. In the case of a
+Linux kernel, this means all of BIOS, any option ROMs, the
+bootloader and the boot config. In practice, this is a lot of
+code/data, much of which is subject to change from boot to boot
+(e.g. changing NICs may change option ROMs). Without reference
+hashes, these measurement changes are difficult to assess or
+confirm as benign. This process also does not provide DMA
+protection, memory configuration/alias checks and locks, crash
+protection, or policy support.
+
+By using the hardware-based root of trust that Intel TXT provides,
+many of these issues can be mitigated. Specifically: many
+pre-launch components can be removed from the trust chain, DMA
+protection is provided to all launched components, a large number
+of platform configuration checks are performed and values locked,
+protection is provided for any data in the event of an improper
+shutdown, and there is support for policy-based execution/verification.
+This provides a more stable measurement and a higher assurance of
+system configuration and initial state than would be otherwise
+possible. Since the tboot project is open source, source code for
+almost all parts of the trust chain is available (excepting SMM and
+Intel-provided firmware).
+
+How Does it Work?
+=================
+
+o Tboot is an executable that is launched by the bootloader as
+ the "kernel" (the binary the bootloader executes).
+o It performs all of the work necessary to determine if the
+ platform supports Intel TXT and, if so, executes the GETSEC[SENTER]
+ processor instruction that initiates the dynamic root of trust.
+ - If tboot determines that the system does not support Intel TXT
+ or is not configured correctly (e.g. the SINIT AC Module was
+ incorrect), it will directly launch the kernel with no changes
+ to any state.
+ - Tboot will output various information about its progress to the
+ terminal, serial port, and/or an in-memory log; the output
+ locations can be configured with a command line switch.
+o The GETSEC[SENTER] instruction will return control to tboot and
+ tboot then verifies certain aspects of the environment (e.g. TPM NV
+ lock, e820 table does not have invalid entries, etc.).
+o It will wake the APs from the special sleep state the GETSEC[SENTER]
+ instruction had put them in and place them into a wait-for-SIPI
+ state.
+ - Because the processors will not respond to an INIT or SIPI when
+ in the TXT environment, it is necessary to create a small VT-x
+ guest for the APs. When they run in this guest, they will
+ simply wait for the INIT-SIPI-SIPI sequence, which will cause
+ VMEXITs, and then disable VT and jump to the SIPI vector. This
+ approach seemed like a better choice than having to insert
+ special code into the kernel's MP wakeup sequence.
+o Tboot then applies an (optional) user-defined launch policy to
+ verify the kernel and initrd.
+ - This policy is rooted in TPM NV and is described in the tboot
+ project. The tboot project also contains code for tools to
+ create and provision the policy.
+ - Policies are completely under user control and if not present
+ then any kernel will be launched.
+ - Policy action is flexible and can include halting on failures
+ or simply logging them and continuing.
+o Tboot adjusts the e820 table provided by the bootloader to reserve
+ its own location in memory as well as to reserve certain other
+ TXT-related regions.
+o As part of it's launch, tboot DMA protects all of RAM (using the
+ VT-d PMRs). Thus, the kernel must be booted with 'intel_iommu=on'
+ in order to remove this blanket protection and use VT-d's
+ page-level protection.
+o Tboot will populate a shared page with some data about itself and
+ pass this to the Linux kernel as it transfers control.
+ - The location of the shared page is passed via the boot_params
+ struct as a physical address.
+o The kernel will look for the tboot shared page address and, if it
+ exists, map it.
+o As one of the checks/protections provided by TXT, it makes a copy
+ of the VT-d DMARs in a DMA-protected region of memory and verifies
+ them for correctness. The VT-d code will detect if the kernel was
+ launched with tboot and use this copy instead of the one in the
+ ACPI table.
+o At this point, tboot and TXT are out of the picture until a
+ shutdown (S<n>)
+o In order to put a system into any of the sleep states after a TXT
+ launch, TXT must first be exited. This is to prevent attacks that
+ attempt to crash the system to gain control on reboot and steal
+ data left in memory.
+ - The kernel will perform all of its sleep preparation and
+ populate the shared page with the ACPI data needed to put the
+ platform in the desired sleep state.
+ - Then the kernel jumps into tboot via the vector specified in the
+ shared page.
+ - Tboot will clean up the environment and disable TXT, then use the
+ kernel-provided ACPI information to actually place the platform
+ into the desired sleep state.
+ - In the case of S3, tboot will also register itself as the resume
+ vector. This is necessary because it must re-establish the
+ measured environment upon resume. Once the TXT environment
+ has been restored, it will restore the TPM PCRs and then
+ transfer control back to the kernel's S3 resume vector.
+ In order to preserve system integrity across S3, the kernel
+ provides tboot with a set of memory ranges (kernel
+ code/data/bss, S3 resume code, and AP trampoline) that tboot
+ will calculate a MAC (message authentication code) over and then
+ seal with the TPM. On resume and once the measured environment
+ has been re-established, tboot will re-calculate the MAC and
+ verify it against the sealed value. Tboot's policy determines
+ what happens if the verification fails.
+
+That's pretty much it for TXT support.
+
+
+Configuring the System:
+======================
+
+This code works with 32bit, 32bit PAE, and 64bit (x86_64) kernels.
+
+In BIOS, the user must enable: TPM, TXT, VT-x, VT-d. Not all BIOSes
+allow these to be individually enabled/disabled and the screens in
+which to find them are BIOS-specific.
+
+grub.conf needs to be modified as follows:
+ title Linux 2.6.29-tip w/ tboot
+ root (hd0,0)
+ kernel /tboot.gz logging=serial,vga,memory
+ module /vmlinuz-2.6.29-tip intel_iommu=on ro
+ root=LABEL=/ rhgb console=ttyS0,115200 3
+ module /initrd-2.6.29-tip.img
+ module /Q35_SINIT_17.BIN
+
+The kernel option for enabling Intel TXT support is found under the
+Security top-level menu and is called "Enable Intel(R) Trusted
+Execution Technology (TXT)". It is marked as EXPERIMENTAL and
+depends on the generic x86 support (to allow maximum flexibility in
+kernel build options), since the tboot code will detect whether the
+platform actually supports Intel TXT and thus whether any of the
+kernel code is executed.
+
+The Q35_SINIT_17.BIN file is what Intel TXT refers to as an
+Authenticated Code Module. It is specific to the chipset in the
+system and can also be found on the Trusted Boot site. It is an
+(unencrypted) module signed by Intel that is used as part of the
+DRTM process to verify and configure the system. It is signed
+because it operates at a higher privilege level in the system than
+any other macrocode and its correct operation is critical to the
+establishment of the DRTM. The process for determining the correct
+SINIT ACM for a system is documented in the SINIT-guide.txt file
+that is on the tboot SourceForge site under the SINIT ACM downloads.
000/040 ALL screen_info Text mode or frame buffer information
(struct screen_info)
040/014 ALL apm_bios_info APM BIOS information (struct apm_bios_info)
+058/008 ALL tboot_addr Physical address of tboot shared page
060/010 ALL ist_info Intel SpeedStep (IST) BIOS support information
(struct ist_info)
080/010 ALL hd0_info hd0 disk parameter, OBSOLETE!!
config ARCH_SUPPORTS_DEBUG_PAGEALLOC
def_bool y
+config HAVE_INTEL_TXT
+ def_bool y
+ depends on EXPERIMENTAL && DMAR && ACPI
+
# Use the generic interrupt handling code in kernel/irq/:
config GENERIC_HARDIRQS
bool
struct boot_params {
struct screen_info screen_info; /* 0x000 */
struct apm_bios_info apm_bios_info; /* 0x040 */
- __u8 _pad2[12]; /* 0x054 */
+ __u8 _pad2[4]; /* 0x054 */
+ __u64 tboot_addr; /* 0x058 */
struct ist_info ist_info; /* 0x060 */
__u8 _pad3[16]; /* 0x070 */
__u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
#endif
#ifdef CONFIG_X86_32
FIX_WP_TEST,
+#endif
+#ifdef CONFIG_INTEL_TXT
+ FIX_TBOOT_BASE,
#endif
__end_of_fixed_addresses
};
obj-$(CONFIG_X86_32) += tls.o
obj-$(CONFIG_IA32_EMULATION) += tls.o
obj-y += step.o
+obj-$(CONFIG_INTEL_TXT) += tboot.o
obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-y += cpu/
obj-y += acpi/
#include <linux/pm.h>
#include <linux/efi.h>
#include <linux/dmi.h>
+#include <linux/tboot.h>
#include <acpi/reboot.h>
#include <asm/io.h>
#include <asm/apic.h>
if (reboot_emergency)
emergency_vmx_disable_all();
+ tboot_shutdown(TB_SHUTDOWN_REBOOT);
+
/* Tell the BIOS if we want cold or warm reboot */
*((unsigned short *)__va(0x472)) = reboot_mode;
/* stop other cpus and apics */
machine_shutdown();
+ tboot_shutdown(TB_SHUTDOWN_HALT);
+
/* stop this cpu */
stop_this_cpu(NULL);
}
machine_shutdown();
pm_power_off();
}
+ /* a fallback in case there is no PM info available */
+ tboot_shutdown(TB_SHUTDOWN_HALT);
}
struct machine_ops machine_ops = {
#include <linux/percpu.h>
#include <linux/crash_dump.h>
+#include <linux/tboot.h>
#include <video/edid.h>
paravirt_pagetable_setup_done(swapper_pg_dir);
paravirt_post_allocator_init();
+ tboot_probe();
+
#ifdef CONFIG_X86_64
map_vsyscall();
#endif
#include <linux/bootmem.h>
#include <linux/err.h>
#include <linux/nmi.h>
+#include <linux/tboot.h>
#include <asm/acpi.h>
#include <asm/desc.h>
void native_play_dead(void)
{
play_dead_common();
+ tboot_shutdown(TB_SHUTDOWN_WFS);
wbinvd_halt();
}
--- /dev/null
+/*
+ * 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
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/dma_remapping.h>
+#include <linux/init_task.h>
+#include <linux/spinlock.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 <asm/trampoline.h>
+#include <asm/processor.h>
+#include <asm/bootparam.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/fixmap.h>
+#include <asm/proto.h>
+#include <asm/setup.h>
+#include <asm/e820.h>
+#include <asm/io.h>
+
+#include "acpi/realmode/wakeup.h"
+
+/* Global pointer to shared data; NULL means no measured launch. */
+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;
+
+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_any_mapped(boot_params.tboot_addr,
+ boot_params.tboot_addr, E820_RESERVED)) {
+ pr_warning("non-0 tboot_addr but it is not of type E820_RESERVED\n");
+ return;
+ }
+
+ /* only a natively booted kernel should be using TXT */
+ if (paravirt_enabled()) {
+ pr_warning("non-0 tboot_addr but pv_ops is enabled\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),
+ .cpu_vm_mask = CPU_MASK_ALL,
+};
+
+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;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *pte;
+
+ pgd = pgd_offset(&tboot_mm, vaddr);
+ pud = pud_alloc(&tboot_mm, pgd, 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);
+ 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 (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)
+{
+ tboot->num_mac_regions = 0;
+
+ /* S3 resume code */
+ add_mac_region(acpi_wakeup_address, WAKEUP_SIZE);
+
+#ifdef CONFIG_X86_TRAMPOLINE
+ /* AP trampoline code */
+ add_mac_region(virt_to_phys(trampoline_base), TRAMPOLINE_SIZE);
+#endif
+
+ /* kernel code + data + bss */
+ add_mac_region(virt_to_phys(_text), _end - _text);
+
+ tboot->acpi_sinfo.kernel_s3_resume_vector = acpi_wakeup_address;
+
+ 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);
+}
+
+void 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;
+
+ 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;
+ }
+
+ tboot_shutdown(acpi_shutdown_map[sleep_state]);
+}
+
+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 __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
+ unsigned long action, void *hcpu)
+{
+ switch (action) {
+ case CPU_DYING:
+ atomic_inc(&ap_wfs_count);
+ if (num_online_cpus() == 1)
+ if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
+ return NOTIFY_BAD;
+ break;
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block tboot_cpu_notifier __cpuinitdata =
+{
+ .notifier_call = tboot_cpu_callback,
+};
+
+static __init int tboot_late_init(void)
+{
+ if (!tboot_enabled())
+ return 0;
+
+ tboot_create_trampoline();
+
+ atomic_set(&ap_wfs_count, 0);
+ register_hotcpu_notifier(&tboot_cpu_notifier);
+ 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 (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;
+}
#include <acpi/acpi.h>
#include "accommon.h"
#include "actables.h"
+#include <linux/tboot.h>
#define _COMPONENT ACPI_HARDWARE
ACPI_MODULE_NAME("hwsleep")
ACPI_FLUSH_CPU_CACHE();
+ tboot_sleep(sleep_state, pm1a_control, pm1b_control);
+
/* Write #2: Write both SLP_TYP + SLP_EN */
status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
#include <linux/timer.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
+#include <linux/tboot.h>
#undef PREFIX
#define PREFIX "DMAR:"
*/
dmar_table_detect();
+ /*
+ * ACPI tables may not be DMA protected by tboot, so use DMAR copy
+ * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
+ */
+ dmar_tbl = tboot_get_dmar_table(dmar_tbl);
+
dmar = (struct acpi_table_dmar *)dmar_tbl;
if (!dmar)
return -ENODEV;
#include <linux/iommu.h>
#include <linux/intel-iommu.h>
#include <linux/sysdev.h>
+#include <linux/tboot.h>
#include <asm/cacheflush.h>
#include <asm/iommu.h>
#include "pci.h"
int __init intel_iommu_init(void)
{
int ret = 0;
+ int force_on = 0;
- if (dmar_table_init())
+ /* VT-d is required for a TXT/tboot launch, so enforce that */
+ force_on = tboot_force_iommu();
+
+ if (dmar_table_init()) {
+ if (force_on)
+ panic("tboot: Failed to initialize DMAR table\n");
return -ENODEV;
+ }
- if (dmar_dev_scope_init())
+ if (dmar_dev_scope_init()) {
+ if (force_on)
+ panic("tboot: Failed to initialize DMAR device scope\n");
return -ENODEV;
+ }
/*
* Check the need for DMA-remapping initialization now.
ret = init_dmars();
if (ret) {
+ if (force_on)
+ panic("tboot: Failed to initialize DMARs\n");
printk(KERN_ERR "IOMMU: dmar init failed\n");
put_iova_domain(&reserved_iova_list);
iommu_exit_mempool();
--- /dev/null
+/*
+ * tboot.h: shared data structure with tboot and kernel and functions
+ * used by kernel for runtime support of Intel(R) Trusted
+ * Execution Technology
+ *
+ * Copyright (c) 2006-2009, Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef _LINUX_TBOOT_H
+#define _LINUX_TBOOT_H
+
+/* these must have the values from 0-5 in this order */
+enum {
+ TB_SHUTDOWN_REBOOT = 0,
+ TB_SHUTDOWN_S5,
+ TB_SHUTDOWN_S4,
+ TB_SHUTDOWN_S3,
+ TB_SHUTDOWN_HALT,
+ TB_SHUTDOWN_WFS
+};
+
+#ifdef CONFIG_INTEL_TXT
+#include <acpi/acpi.h>
+/* used to communicate between tboot and the launched kernel */
+
+#define TB_KEY_SIZE 64 /* 512 bits */
+
+#define MAX_TB_MAC_REGIONS 32
+
+struct tboot_mac_region {
+ u64 start; /* must be 64 byte -aligned */
+ u32 size; /* must be 64 byte -granular */
+} __packed;
+
+/* GAS - Generic Address Structure (ACPI 2.0+) */
+struct tboot_acpi_generic_address {
+ u8 space_id;
+ u8 bit_width;
+ u8 bit_offset;
+ u8 access_width;
+ u64 address;
+} __packed;
+
+/*
+ * combines Sx info from FADT and FACS tables per ACPI 2.0+ spec
+ * (http://www.acpi.info/)
+ */
+struct tboot_acpi_sleep_info {
+ struct tboot_acpi_generic_address pm1a_cnt_blk;
+ struct tboot_acpi_generic_address pm1b_cnt_blk;
+ struct tboot_acpi_generic_address pm1a_evt_blk;
+ struct tboot_acpi_generic_address pm1b_evt_blk;
+ u16 pm1a_cnt_val;
+ u16 pm1b_cnt_val;
+ u64 wakeup_vector;
+ u32 vector_width;
+ u64 kernel_s3_resume_vector;
+} __packed;
+
+/*
+ * shared memory page used for communication between tboot and kernel
+ */
+struct tboot {
+ /*
+ * version 3+ fields:
+ */
+
+ /* TBOOT_UUID */
+ u8 uuid[16];
+
+ /* version number: 5 is current */
+ u32 version;
+
+ /* physical addr of tb_log_t log */
+ u32 log_addr;
+
+ /*
+ * physical addr of entry point for tboot shutdown and
+ * type of shutdown (TB_SHUTDOWN_*) being requested
+ */
+ u32 shutdown_entry;
+ u32 shutdown_type;
+
+ /* kernel-specified ACPI info for Sx shutdown */
+ struct tboot_acpi_sleep_info acpi_sinfo;
+
+ /* tboot location in memory (physical) */
+ u32 tboot_base;
+ u32 tboot_size;
+
+ /* memory regions (phys addrs) for tboot to MAC on S3 */
+ u8 num_mac_regions;
+ struct tboot_mac_region mac_regions[MAX_TB_MAC_REGIONS];
+
+
+ /*
+ * version 4+ fields:
+ */
+
+ /* symmetric key for use by kernel; will be encrypted on S3 */
+ u8 s3_key[TB_KEY_SIZE];
+
+
+ /*
+ * version 5+ fields:
+ */
+
+ /* used to 4byte-align num_in_wfs */
+ u8 reserved_align[3];
+
+ /* number of processors in wait-for-SIPI */
+ u32 num_in_wfs;
+} __packed;
+
+/*
+ * UUID for tboot data struct to facilitate matching
+ * defined as {663C8DFF-E8B3-4b82-AABF-19EA4D057A08} by tboot, which is
+ * represented as {} in the char array used here
+ */
+#define TBOOT_UUID {0xff, 0x8d, 0x3c, 0x66, 0xb3, 0xe8, 0x82, 0x4b, 0xbf,\
+ 0xaa, 0x19, 0xea, 0x4d, 0x5, 0x7a, 0x8}
+
+extern struct tboot *tboot;
+
+static inline int tboot_enabled(void)
+{
+ return tboot != NULL;
+}
+
+extern void tboot_probe(void);
+extern void tboot_shutdown(u32 shutdown_type);
+extern void tboot_sleep(u8 sleep_state, u32 pm1a_control, u32 pm1b_control);
+extern struct acpi_table_header *tboot_get_dmar_table(
+ struct acpi_table_header *dmar_tbl);
+extern int tboot_force_iommu(void);
+
+#else
+
+#define tboot_probe() do { } while (0)
+#define tboot_shutdown(shutdown_type) do { } while (0)
+#define tboot_sleep(sleep_state, pm1a_control, pm1b_control) \
+ do { } while (0)
+#define tboot_get_dmar_table(dmar_tbl) (dmar_tbl)
+#define tboot_force_iommu() 0
+
+#endif /* !CONFIG_INTEL_TXT */
+
+#endif /* _LINUX_TBOOT_H */
break;
}
}
+
if (!error) {
BUG_ON(num_online_cpus() > 1);
/* Make sure the CPUs won't be enabled by someone else */
If you are unsure how to answer this question, answer N.
+config INTEL_TXT
+ bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
+ depends on HAVE_INTEL_TXT
+ help
+ This option enables support for booting the kernel with the
+ Trusted Boot (tboot) module. This will utilize
+ Intel(R) Trusted Execution Technology to perform a measured launch
+ of the kernel. If the system does not support Intel(R) TXT, this
+ will have no effect.
+
+ Intel TXT will provide higher assurance of system configuration and
+ initial state as well as data reset protection. This is used to
+ create a robust initial kernel measurement and verification, which
+ helps to ensure that kernel security mechanisms are functioning
+ correctly. This level of protection requires a root of trust outside
+ of the kernel itself.
+
+ Intel TXT also helps solve real end user concerns about having
+ confidence that their hardware is running the VMM or kernel that
+ it was configured with, especially since they may be responsible for
+ providing such assurances to VMs and services running on it.
+
+ See <http://www.intel.com/technology/security/> for more information
+ about Intel(R) TXT.
+ See <http://tboot.sourceforge.net> for more information about tboot.
+ See Documentation/intel_txt.txt for a description of how to enable
+ Intel TXT support in a kernel boot.
+
+ If you are unsure as to whether this is required, answer N.
+
config LSM_MMAP_MIN_ADDR
int "Low address space for LSM to protect from user allocation"
depends on SECURITY && SECURITY_SELINUX
projects / linux-2.6-block.git / commitdiff