Linux support for Intel(R) Trusted Execution Technology.
Documentation/intel_txt.txt | 187 +++++++++++++++++++++++
Documentation/x86/zero-page.txt | 1
arch/x86/include/asm/bootparam.h | 3
arch/x86/include/asm/fixmap.h | 3
arch/x86/include/asm/tboot.h | 159 ++++++++++++++++++++
arch/x86/kernel/Makefile | 1
arch/x86/kernel/reboot.c | 14 +
arch/x86/kernel/setup.c | 4
arch/x86/kernel/smpboot.c | 6
arch/x86/kernel/tboot.c | 308 +++++++++++++++++++++++++++++++++++++++
drivers/acpi/acpica/hwsleep.c | 35 ++++
drivers/pci/dmar.c | 6
drivers/pci/intel-iommu.c | 26 +++
init/main.c | 3
kernel/cpu.c | 6
security/Kconfig | 22 ++
16 files changed, 777 insertions(+), 7 deletions(-)
Signed-off-by: Joseph Cihula <[email protected]>
Signed-off-by: Shane Wang <[email protected]>
Signed-off-by: Gang Wei <[email protected]>
---
diff -uprN linux-2.6.30-rc8/arch/x86/include/asm/bootparam.h linux-2.6.30-rc8-patched/arch/x86/include/asm/bootparam.h
--- linux-2.6.30-rc8/arch/x86/include/asm/bootparam.h 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/arch/x86/include/asm/bootparam.h 2009-06-05 08:38:03.000000000 -0700
@@ -84,7 +84,8 @@ struct efi_info {
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_shared_addr; /* 0x058 */
struct ist_info ist_info; /* 0x060 */
__u8 _pad3[16]; /* 0x070 */
__u8 hd0_info[16]; /* obsolete! */ /* 0x080 */
diff -uprN linux-2.6.30-rc8/arch/x86/include/asm/fixmap.h linux-2.6.30-rc8-patched/arch/x86/include/asm/fixmap.h
--- linux-2.6.30-rc8/arch/x86/include/asm/fixmap.h 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/arch/x86/include/asm/fixmap.h 2009-06-05 08:38:03.000000000 -0700
@@ -132,6 +132,9 @@ enum fixed_addresses {
#ifdef CONFIG_X86_32
FIX_WP_TEST,
#endif
+#ifdef CONFIG_INTEL_TXT
+ FIX_TBOOT_SHARED_BASE,
+#endif
__end_of_fixed_addresses
};
diff -uprN linux-2.6.30-rc8/arch/x86/include/asm/tboot.h linux-2.6.30-rc8-patched/arch/x86/include/asm/tboot.h
--- linux-2.6.30-rc8/arch/x86/include/asm/tboot.h 1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.30-rc8-patched/arch/x86/include/asm/tboot.h 2009-06-05 08:38:03.000000000 -0700
@@ -0,0 +1,159 @@
+/*
+ * 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 _ASM_TBOOT_H
+#define _ASM_TBOOT_H
+
+#include <acpi/acpi.h>
+
+#define TB_SHUTDOWN_REBOOT 0
+#define TB_SHUTDOWN_S5 1
+#define TB_SHUTDOWN_S4 2
+#define TB_SHUTDOWN_S3 3
+#define TB_SHUTDOWN_HALT 4
+#define TB_SHUTDOWN_WFS 5
+
+#ifdef CONFIG_INTEL_TXT
+
+struct tboot_uuid {
+ u32 data1;
+ u16 data2;
+ u16 data3;
+ u16 data4;
+ u8 data5[6];
+} __packed;
+
+/* 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_shared {
+ /* version 3+ fields: */
+ struct tboot_uuid uuid; /* TBOOT_SHARED_UUID */
+ u32 version; /* Version number: 5 is current */
+ u32 log_addr; /* physical addr of tb_log_t log */
+ u32 shutdown_entry; /* entry point for tboot shutdown */
+ u32 shutdown_type; /* type of shutdown (TB_SHUTDOWN_*) */
+ struct tboot_acpi_sleep_info
+ acpi_sinfo; /* where kernel put acpi sleep info in Sx */
+ u32 tboot_base; /* starting addr for tboot */
+ u32 tboot_size; /* size of tboot */
+ u8 num_mac_regions; /* number mem regions to MAC on S3 */
+ /* contig regions memory to MAC on S3 */
+ struct tboot_mac_region mac_regions[MAX_TB_MAC_REGIONS];
+ /* version 4+ fields: */
+ /* populated by tboot; will be encrypted */
+ u8 s3_key[TB_KEY_SIZE];
+ /* version 5+ fields: */
+ u8 reserved_align[3]; /* used to 4byte-align num_in_wfs */
+ u32 num_in_wfs; /* number of processors in wait-for-SIPI */
+} __packed;
+
+/* UUID for tboot_shared data struct to facilitate matching */
+/* {663C8DFF-E8B3-4b82-AABF-19EA4D057A08} */
+#define TBOOT_SHARED_UUID \
+ ((struct tboot_uuid){ 0x663c8dff, 0xe8b3, 0x4b82, 0xaabf, \
+ { 0x19, 0xea, 0x4d, 0x5, 0x7a, 0x8 } })
+
+extern struct tboot_shared *tboot_shared;
+
+static inline int tboot_in_measured_env(void)
+{
+ return tboot_shared != NULL;
+}
+
+extern void tboot_probe(void);
+extern void tboot_create_trampoline(void);
+extern void tboot_shutdown(u32 shutdown_type);
+extern void tboot_sleep(u8 sleep_state);
+extern void tboot_wait_for_aps(int num_aps);
+extern struct acpi_table_header *tboot_get_dmar_table(void);
+
+#else /* CONFIG_INTEL_TXT */
+
+static inline int tboot_in_measured_env(void)
+{
+ return 0;
+}
+
+static inline void tboot_probe(void)
+{
+}
+
+static inline void tboot_create_trampoline(void)
+{
+}
+
+static inline void tboot_shutdown(u32 shutdown_type)
+{
+}
+
+static inline void tboot_sleep(u8 sleep_state)
+{
+}
+
+static inline void tboot_wait_for_aps(int num_aps)
+{
+}
+
+static inline struct acpi_table_header *tboot_get_dmar_table(void)
+{
+ return NULL;
+}
+
+#endif /* !CONFIG_INTEL_TXT */
+
+#endif /* _ASM_TBOOT_H */
diff -uprN linux-2.6.30-rc8/arch/x86/kernel/Makefile linux-2.6.30-rc8-patched/arch/x86/kernel/Makefile
--- linux-2.6.30-rc8/arch/x86/kernel/Makefile 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/arch/x86/kernel/Makefile 2009-06-05 08:38:03.000000000 -0700
@@ -47,6 +47,7 @@ obj-$(CONFIG_X86_DS) += ds.o
obj-$(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/
diff -uprN linux-2.6.30-rc8/arch/x86/kernel/reboot.c linux-2.6.30-rc8-patched/arch/x86/kernel/reboot.c
--- linux-2.6.30-rc8/arch/x86/kernel/reboot.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/arch/x86/kernel/reboot.c 2009-06-05 08:38:03.000000000 -0700
@@ -24,6 +24,8 @@
# include <asm/iommu.h>
#endif
+#include <asm/tboot.h>
+
/*
* Power off function, if any
*/
@@ -451,6 +453,8 @@ static void native_machine_emergency_res
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;
@@ -516,11 +520,13 @@ static void native_machine_emergency_res
void native_machine_shutdown(void)
{
- /* Stop the cpus and apics */
#ifdef CONFIG_SMP
-
/* The boot cpu is always logical cpu 0 */
int reboot_cpu_id = 0;
+#endif
+
+ /* Stop the cpus and apics */
+#ifdef CONFIG_SMP
#ifdef CONFIG_X86_32
/* See if there has been given a command line override */
@@ -577,6 +583,8 @@ static void native_machine_halt(void)
/* stop other cpus and apics */
machine_shutdown();
+ tboot_shutdown(TB_SHUTDOWN_HALT);
+
/* stop this cpu */
stop_this_cpu(NULL);
}
@@ -588,6 +596,8 @@ static void native_machine_power_off(voi
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 = {
diff -uprN linux-2.6.30-rc8/arch/x86/kernel/setup.c linux-2.6.30-rc8-patched/arch/x86/kernel/setup.c
--- linux-2.6.30-rc8/arch/x86/kernel/setup.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/arch/x86/kernel/setup.c 2009-06-05 08:38:03.000000000 -0700
@@ -137,6 +137,8 @@ struct boot_params __initdata boot_param
struct boot_params boot_params;
#endif
+#include <asm/tboot.h>
+
/*
* Machine setup..
*/
@@ -939,6 +941,8 @@ void __init setup_arch(char **cmdline_p)
paravirt_pagetable_setup_done(swapper_pg_dir);
paravirt_post_allocator_init();
+ tboot_probe();
+
#ifdef CONFIG_X86_64
map_vsyscall();
#endif
diff -uprN linux-2.6.30-rc8/arch/x86/kernel/smpboot.c linux-2.6.30-rc8-patched/arch/x86/kernel/smpboot.c
--- linux-2.6.30-rc8/arch/x86/kernel/smpboot.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/arch/x86/kernel/smpboot.c 2009-06-05 08:38:03.000000000 -0700
@@ -62,6 +62,7 @@
#include <asm/vmi.h>
#include <asm/apic.h>
#include <asm/setup.h>
+#include <asm/tboot.h>
#include <asm/uv/uv.h>
#include <linux/mc146818rtc.h>
@@ -1313,7 +1314,10 @@ void play_dead_common(void)
void native_play_dead(void)
{
play_dead_common();
- wbinvd_halt();
+ if (tboot_in_measured_env())
+ tboot_shutdown(TB_SHUTDOWN_WFS);
+ else
+ wbinvd_halt();
}
#else /* ... !CONFIG_HOTPLUG_CPU */
diff -uprN linux-2.6.30-rc8/arch/x86/kernel/tboot.c linux-2.6.30-rc8-patched/arch/x86/kernel/tboot.c
--- linux-2.6.30-rc8/arch/x86/kernel/tboot.c 1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.30-rc8-patched/arch/x86/kernel/tboot.c 2009-06-05 12:06:44.000000000 -0700
@@ -0,0 +1,308 @@
+/*
+ * 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/init.h>
+#include <linux/sched.h>
+#include <linux/pfn.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/init_task.h>
+
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/processor.h>
+#include <asm/bootparam.h>
+#include <asm/setup.h>
+#include <asm/io.h>
+#include <asm/e820.h>
+#include <asm/tboot.h>
+
+/* Global pointer to shared data; NULL means no measured launch. */
+struct tboot_shared *tboot_shared __read_mostly;
+
+void __init tboot_probe(void)
+{
+ static struct tboot_uuid tboot_shared_uuid __initdata =
+ TBOOT_SHARED_UUID;
+
+ /* Look for valid page-aligned address for shared page. */
+ if (boot_params.tboot_shared_addr == 0)
+ 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_shared_addr,
+ boot_params.tboot_shared_addr, E820_UNUSABLE)) {
+ printk(KERN_WARNING "TXT: non-0 tboot_shared_addr but it is not of type E820_UNUSABLE\n");
+ return;
+ }
+
+ /* only a natively booted kernel should be using TXT */
+ if (paravirt_enabled()) {
+ printk(KERN_WARNING "TXT: non-0 tboot_shared_addr but pv_ops is enabled\n");
+ return;
+ }
+
+ /* Map and check for tboot UUID. */
+ set_fixmap(FIX_TBOOT_SHARED_BASE, boot_params.tboot_shared_addr);
+ tboot_shared = (struct tboot_shared *)
+ fix_to_virt(FIX_TBOOT_SHARED_BASE);
+ if (memcmp(&tboot_shared_uuid, &tboot_shared->uuid,
+ sizeof(struct tboot_uuid))) {
+ printk(KERN_WARNING "TXT: tboot_shared at 0x%llx is invalid\n",
+ boot_params.tboot_shared_addr);
+ tboot_shared = NULL;
+ return;
+ }
+ if (tboot_shared->version < 5) {
+ printk(KERN_WARNING "TXT: tboot_shared version is invalid: %u\n",
+ tboot_shared->version);
+ tboot_shared = NULL;
+ return;
+ }
+
+ printk(KERN_INFO "TXT: found shared page at phys addr 0x%llx:\n",
+ boot_params.tboot_shared_addr);
+ printk(KERN_DEBUG "TXT: version: %d\n", tboot_shared->version);
+ printk(KERN_DEBUG "TXT: log_addr: 0x%08x\n", tboot_shared->log_addr);
+ printk(KERN_DEBUG "TXT: shutdown_entry: 0x%x\n",
+ tboot_shared->shutdown_entry);
+ printk(KERN_DEBUG "TXT: tboot_base: 0x%08x\n",
+ tboot_shared->tboot_base);
+ printk(KERN_DEBUG "TXT: tboot_size: 0x%x\n",
+ tboot_shared->tboot_size);
+}
+
+static pgd_t *tboot_pg_dir;
+static struct mm_struct tboot_mm = INIT_MM(tboot_mm);
+
+static inline void switch_to_tboot_pt(void)
+{
+ write_cr3(virt_to_phys(tboot_pg_dir));
+}
+
+static int map_page_for_tboot(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_pages_for_tboot(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_page_for_tboot(vaddr, start_pfn, PAGE_KERNEL_EXEC))
+ return -1;
+ }
+
+ return 0;
+}
+
+void tboot_create_trampoline(void)
+{
+ u32 map_base, map_size;
+
+ if (!tboot_in_measured_env())
+ return;
+
+ /* Create identity map for tboot shutdown code. */
+ map_base = PFN_DOWN(tboot_shared->tboot_base);
+ map_size = PFN_UP(tboot_shared->tboot_size);
+ if (map_pages_for_tboot(map_base << PAGE_SHIFT, map_base,
+ map_size))
+ panic(KERN_ERR "TXT: Error mapping tboot pages (mfns) @ 0x%x, 0x%x\n", map_base, map_size);
+}
+
+#include "acpi/realmode/wakeup.h"
+#include <asm/trampoline.h>
+
+void tboot_shutdown(u32 shutdown_type)
+{
+ if (!tboot_in_measured_env())
+ 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) {
+ tboot_shared->num_mac_regions = 3;
+ /* S3 resume code */
+ tboot_shared->mac_regions[0].start =
+ PFN_PHYS(PFN_DOWN(acpi_wakeup_address));
+ tboot_shared->mac_regions[0].size =
+ PFN_UP(WAKEUP_SIZE) << PAGE_SHIFT;
+ /* AP trampoline code */
+ tboot_shared->mac_regions[1].start =
+ PFN_PHYS(PFN_DOWN(virt_to_phys(trampoline_base)));
+ tboot_shared->mac_regions[1].size =
+ PFN_UP(TRAMPOLINE_SIZE) << PAGE_SHIFT;
+ /* kernel code + data + bss */
+ tboot_shared->mac_regions[2].start =
+ PFN_PHYS(PFN_DOWN(virt_to_phys(&_text)));
+ tboot_shared->mac_regions[2].size =
+ PFN_PHYS(PFN_UP(virt_to_phys(&_end))) -
+ PFN_PHYS(PFN_DOWN(virt_to_phys(&_text)));
+ }
+
+ tboot_shared->shutdown_type = shutdown_type;
+
+ switch_to_tboot_pt();
+
+ ((void(*)(void))(unsigned long)tboot_shared->shutdown_entry)();
+
+ /* should not reach here */
+ while (1)
+ halt();
+}
+
+void tboot_sleep(u8 sleep_state)
+{
+ 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 (sleep_state >= ACPI_S_STATE_COUNT ||
+ acpi_shutdown_map[sleep_state] == -1) {
+ printk(KERN_WARNING "TXT: unsupported sleep state 0x%x\n",
+ sleep_state);
+ return;
+ }
+
+ tboot_shutdown(acpi_shutdown_map[sleep_state]);
+}
+
+void tboot_wait_for_aps(int num_aps)
+{
+ if (!tboot_in_measured_env())
+ return;
+
+ while (atomic_read((atomic_t *)&tboot_shared->num_in_wfs) != num_aps)
+ cpu_relax();
+}
+
+/*
+ * 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(void)
+{
+ void *heap_base, *heap_ptr, *config;
+ struct acpi_table_header *dmar_table;
+
+ /* 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 == NULL)
+ return NULL;
+
+ /* now map TXT heap */
+ heap_base = ioremap(*(u64 *)(config + TXTCR_HEAP_BASE),
+ *(u64 *)(config + TXTCR_HEAP_SIZE));
+ iounmap(config);
+ if (heap_base == NULL)
+ 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_table = (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_table;
+}
diff -uprN linux-2.6.30-rc8/Documentation/intel_txt.txt linux-2.6.30-rc8-patched/Documentation/intel_txt.txt
--- linux-2.6.30-rc8/Documentation/intel_txt.txt 1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.30-rc8-patched/Documentation/intel_txt.txt 2009-06-05 08:38:03.000000000 -0700
@@ -0,0 +1,187 @@
+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.
diff -uprN linux-2.6.30-rc8/Documentation/x86/zero-page.txt linux-2.6.30-rc8-patched/Documentation/x86/zero-page.txt
--- linux-2.6.30-rc8/Documentation/x86/zero-page.txt 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/Documentation/x86/zero-page.txt 2009-06-05 08:38:03.000000000 -0700
@@ -12,6 +12,7 @@ Offset Proto Name Meaning
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_shared_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!!
diff -uprN linux-2.6.30-rc8/drivers/acpi/acpica/hwsleep.c linux-2.6.30-rc8-patched/drivers/acpi/acpica/hwsleep.c
--- linux-2.6.30-rc8/drivers/acpi/acpica/hwsleep.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/drivers/acpi/acpica/hwsleep.c 2009-06-05 08:38:04.000000000 -0700
@@ -45,6 +45,7 @@
#include <acpi/acpi.h>
#include "accommon.h"
#include "actables.h"
+#include <asm/tboot.h>
#define _COMPONENT ACPI_HARDWARE
ACPI_MODULE_NAME("hwsleep")
@@ -342,6 +343,40 @@ acpi_status asmlinkage acpi_enter_sleep_
ACPI_FLUSH_CPU_CACHE();
+#ifdef CONFIG_INTEL_TXT
+#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;
+
+ if (tboot_in_measured_env()) {
+ TB_COPY_GAS(tboot_shared->acpi_sinfo.pm1a_cnt_blk,
+ acpi_gbl_FADT.xpm1a_control_block);
+ TB_COPY_GAS(tboot_shared->acpi_sinfo.pm1b_cnt_blk,
+ acpi_gbl_FADT.xpm1b_control_block);
+ TB_COPY_GAS(tboot_shared->acpi_sinfo.pm1a_evt_blk,
+ acpi_gbl_FADT.xpm1a_event_block);
+ TB_COPY_GAS(tboot_shared->acpi_sinfo.pm1b_evt_blk,
+ acpi_gbl_FADT.xpm1b_event_block);
+ tboot_shared->acpi_sinfo.pm1a_cnt_val = pm1a_control;
+ tboot_shared->acpi_sinfo.pm1b_cnt_val = pm1b_control;
+ /*
+ * 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_shared->acpi_sinfo.wakeup_vector = acpi_gbl_FADT.facs +
+ offsetof(struct acpi_table_facs, firmware_waking_vector);
+ tboot_shared->acpi_sinfo.vector_width = 32;
+ tboot_shared->acpi_sinfo.kernel_s3_resume_vector =
+ acpi_wakeup_address;
+
+ tboot_sleep(sleep_state);
+ }
+#endif
+
/* Write #2: Write both SLP_TYP + SLP_EN */
status = acpi_hw_write_pm1_control(pm1a_control, pm1b_control);
diff -uprN linux-2.6.30-rc8/drivers/pci/dmar.c linux-2.6.30-rc8-patched/drivers/pci/dmar.c
--- linux-2.6.30-rc8/drivers/pci/dmar.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/drivers/pci/dmar.c 2009-06-05 08:38:04.000000000 -0700
@@ -33,6 +33,7 @@
#include <linux/timer.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
+#include <asm/tboot.h>
#undef PREFIX
#define PREFIX "DMAR:"
@@ -329,6 +330,11 @@ parse_dmar_table(void)
*/
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) */
+ if (tboot_in_measured_env())
+ dmar_tbl = tboot_get_dmar_table();
+
dmar = (struct acpi_table_dmar *)dmar_tbl;
if (!dmar)
return -ENODEV;
diff -uprN linux-2.6.30-rc8/drivers/pci/intel-iommu.c linux-2.6.30-rc8-patched/drivers/pci/intel-iommu.c
--- linux-2.6.30-rc8/drivers/pci/intel-iommu.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/drivers/pci/intel-iommu.c 2009-06-05 08:38:04.000000000 -0700
@@ -38,6 +38,7 @@
#include <linux/intel-iommu.h>
#include <linux/sysdev.h>
#include <asm/cacheflush.h>
+#include <asm/tboot.h>
#include <asm/iommu.h>
#include "pci.h"
@@ -2780,12 +2781,31 @@ static int __init init_iommu_sysfs(void)
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 */
+ if (tboot_in_measured_env()) {
+ if (no_iommu || swiotlb || dmar_disabled)
+ printk(KERN_WARNING "TXT: Forcing Intel-IOMMU to enabled\n");
+ dmar_disabled = 0;
+#ifdef CONFIG_SWIOTLB
+ swiotlb = 0;
+#endif
+ no_iommu = 0;
+ force_on = 1;
+ }
+
+ if (dmar_table_init()) {
+ if (force_on)
+ panic("TXT: Failed to initialize DMAR table\n");
return -ENODEV;
+ }
- if (dmar_dev_scope_init())
+ if (dmar_dev_scope_init()) {
+ if (force_on)
+ panic("TXT: Failed to initialize DMAR device scope\n");
return -ENODEV;
+ }
/*
* Check the need for DMA-remapping initialization now.
@@ -2801,6 +2821,8 @@ int __init intel_iommu_init(void)
ret = init_dmars();
if (ret) {
+ if (force_on)
+ panic("TXT: Failed to initialize DMARs\n");
printk(KERN_ERR "IOMMU: dmar init failed\n");
put_iova_domain(&reserved_iova_list);
iommu_exit_mempool();
diff -uprN linux-2.6.30-rc8/init/main.c linux-2.6.30-rc8-patched/init/main.c
--- linux-2.6.30-rc8/init/main.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/init/main.c 2009-06-05 08:38:04.000000000 -0700
@@ -69,6 +69,7 @@
#include <asm/io.h>
#include <asm/bugs.h>
#include <asm/setup.h>
+#include <asm/tboot.h>
#include <asm/sections.h>
#include <asm/cacheflush.h>
#include <trace/kmemtrace.h>
@@ -695,6 +696,8 @@ asmlinkage void __init start_kernel(void
ftrace_init();
+ tboot_create_trampoline();
+
/* Do the rest non-__init'ed, we're now alive */
rest_init();
}
diff -uprN linux-2.6.30-rc8/kernel/cpu.c linux-2.6.30-rc8-patched/kernel/cpu.c
--- linux-2.6.30-rc8/kernel/cpu.c 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/kernel/cpu.c 2009-06-05 08:38:04.000000000 -0700
@@ -14,6 +14,7 @@
#include <linux/kthread.h>
#include <linux/stop_machine.h>
#include <linux/mutex.h>
+#include <asm/tboot.h>
#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_mask, cpu_present_mask */
@@ -379,7 +380,7 @@ static cpumask_var_t frozen_cpus;
int disable_nonboot_cpus(void)
{
- int cpu, first_cpu, error;
+ int cpu, first_cpu, error, num_cpus = 0;
error = stop_machine_create();
if (error)
@@ -394,6 +395,7 @@ int disable_nonboot_cpus(void)
for_each_online_cpu(cpu) {
if (cpu == first_cpu)
continue;
+ num_cpus++;
error = _cpu_down(cpu, 1);
if (!error) {
cpumask_set_cpu(cpu, frozen_cpus);
@@ -404,6 +406,8 @@ int disable_nonboot_cpus(void)
break;
}
}
+ /* ensure all CPUs have gone into wait-for-SIPI */
+ tboot_wait_for_aps(num_cpus);
if (!error) {
BUG_ON(num_online_cpus() > 1);
/* Make sure the CPUs won't be enabled by someone else */
diff -uprN linux-2.6.30-rc8/security/Kconfig linux-2.6.30-rc8-patched/security/Kconfig
--- linux-2.6.30-rc8/security/Kconfig 2009-06-02 20:07:25.000000000 -0700
+++ linux-2.6.30-rc8-patched/security/Kconfig 2009-06-05 08:38:04.000000000 -0700
@@ -133,6 +133,28 @@ config SECURITY_DEFAULT_MMAP_MIN_ADDR
/proc/sys/vm/mmap_min_addr tunable.
+config INTEL_TXT
+ bool "Enable Intel(R) Trusted Execution Technology (Intel(R) TXT)"
+ depends on EXPERIMENTAL && X86 && DMAR && ACPI
+ 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 sysem configuration and
+ initial state as well as data reset protection. This is used to
+ create a robust initial kernel measurement and verification.
+
+ 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.
+
source security/selinux/Kconfig
source security/smack/Kconfig
source security/tomoyo/Kconfig
On Fri, 5 Jun 2009, Joseph Cihula wrote:
> Linux support for Intel(R) Trusted Execution Technology.
> Signed-off-by: Joseph Cihula <[email protected]>
> Signed-off-by: Shane Wang <[email protected]>
> Signed-off-by: Gang Wei <[email protected]>
Reviewed-by: James Morris <[email protected]>
There have been no comments on this since you posted it, so we might
assume there are no further technical issues.
Ingo, this should probably be merged via your tree.
- James
--
James Morris
<[email protected]>
On Fri, Jun 12, 2009 at 03:12:59PM +1000, James Morris wrote:
> On Fri, 5 Jun 2009, Joseph Cihula wrote:
>
> > Linux support for Intel(R) Trusted Execution Technology.
>
> > Signed-off-by: Joseph Cihula <[email protected]>
> > Signed-off-by: Shane Wang <[email protected]>
> > Signed-off-by: Gang Wei <[email protected]>
>
> Reviewed-by: James Morris <[email protected]>
The earlier version was also reviewed by me and I think Joe addressed
all my concerns.
So it's
Reviewed-by: Andi Kleen <[email protected]>
-Andi
--
[email protected] -- Speaking for myself only.
On Fri 2009-06-12 15:12:59, James Morris wrote:
> On Fri, 5 Jun 2009, Joseph Cihula wrote:
>
> > Linux support for Intel(R) Trusted Execution Technology.
>
> > Signed-off-by: Joseph Cihula <[email protected]>
> > Signed-off-by: Shane Wang <[email protected]>
> > Signed-off-by: Gang Wei <[email protected]>
>
> Reviewed-by: James Morris <[email protected]>
>
> There have been no comments on this since you posted it, so we might
> assume there are no further technical issues.
I believe the code at best useless and at worst dangerous. We don't
merge useless code to the kernel.
What are non-evil uses of this code?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Fri, 19 Jun 2009 17:05:14 +0200, Pavel Machek said:
> On Fri 2009-06-12 15:12:59, James Morris wrote:
> > On Fri, 5 Jun 2009, Joseph Cihula wrote:
> >
> > > Linux support for Intel(R) Trusted Execution Technology.
> >
> > > Signed-off-by: Joseph Cihula <[email protected]>
> > > Signed-off-by: Shane Wang <[email protected]>
> > > Signed-off-by: Gang Wei <[email protected]>
> >
> > Reviewed-by: James Morris <[email protected]>
> >
> > There have been no comments on this since you posted it, so we might
> > assume there are no further technical issues.
>
> I believe the code at best useless and at worst dangerous. We don't
> merge useless code to the kernel.
>
> What are non-evil uses of this code?
Yes, most of the uses contemplated for this are for evil DRM schemes. On the
other hand, the code is equally useful to help make sure that mo miscreant has
snuck evil DRM (or other evil code) in behind my back.
"Somebody has screwed with this kernel image, and you're not booting what you
thought you were booting."
Seems worth it to me.
* Pavel Machek ([email protected]) wrote:
> What are non-evil uses of this code?
The most common use case I've heard requested from real live
customers[1] is...you guessed it...trusted boot.
This is typically in the context of virtualization and data centers or
clouds. The concerns being addressed are:
* confidence that the hardware is running the VMM that the hardware
owner configured it w/, since they are on the hook for providing a
safe service for each VM running on that hardware
* flip side of that is an additional layer protecting against malicious
VM that is using some VMM hole to try and subvert the host w/ a VMM
of their own
thanks,
-chris
--
[1] as opposed to hardware vendors pushing a feature
> "Somebody has screwed with this kernel image, and you're not booting what you
> thought you were booting."
So I screw with your user space - you can't measure enough to make it
save you in a general setup. Too much I can hit changes each boot.
For a tiny number of very special cases that are highly controlled it has
potential uses. Some of those are evil some are ones with meaningful uses
(eg ATM machines) - although attacks there have included hardware attacks
outside the PC components too.
Personally (and I'm sure Intel disagrees with me) my bigger work is that
I can't verify that the magic block of code for tboot is correct.
> Personally (and I'm sure Intel disagrees with me) my bigger work
worry rather ;)
> > > > Linux support for Intel(R) Trusted Execution Technology.
> > >
> > > > Signed-off-by: Joseph Cihula <[email protected]>
> > > > Signed-off-by: Shane Wang <[email protected]>
> > > > Signed-off-by: Gang Wei <[email protected]>
> > >
> > > Reviewed-by: James Morris <[email protected]>
> > >
> > > There have been no comments on this since you posted it, so we might
> > > assume there are no further technical issues.
> >
> > I believe the code at best useless and at worst dangerous. We don't
> > merge useless code to the kernel.
> >
> > What are non-evil uses of this code?
>
> Yes, most of the uses contemplated for this are for evil DRM schemes. On the
> other hand, the code is equally useful to help make sure that mo miscreant has
> snuck evil DRM (or other evil code) in behind my back.
>
> "Somebody has screwed with this kernel image, and you're not booting what you
> thought you were booting."
>
> Seems worth it to me.
Unfortunately, I do not think you can boot linux kernel under TXT
sandbox. (Is there some code that you can boot under TXT sandbox? If
so, where?)
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Fri, 19 Jun 2009, Alan Cox wrote:
> > Personally (and I'm sure Intel disagrees with me) my bigger work
>
> worry rather ;)
Yes, I hope we hear more on the licensing of this blob -- I flagged it a
while back.
- James
--
James Morris
<[email protected]>
On Fri, 19 Jun 2009, Chris Wright wrote:
> * Pavel Machek ([email protected]) wrote:
> > What are non-evil uses of this code?
>
> The most common use case I've heard requested from real live
> customers[1] is...you guessed it...trusted boot.
>
> This is typically in the context of virtualization and data centers or
> clouds. The concerns being addressed are:
>
> * confidence that the hardware is running the VMM that the hardware
> owner configured it w/, since they are on the hook for providing a
> safe service for each VM running on that hardware
>
> * flip side of that is an additional layer protecting against malicious
> VM that is using some VMM hole to try and subvert the host w/ a VMM
> of their own
Agreed. I'd also mention (again), these slides on the topic by Joanna
Rutkowska:
http://invisiblethingslab.com/resources/misc09/trusted_computing_thoughts.pdf
Also, hardware security measures such as TXT are important in providing
stronger mechanisms to ensure that kernel security mechanisms are
functioning correctly.
- James
--
James Morris
<[email protected]>
> Also, hardware security measures such as TXT are important in providing
> stronger mechanisms to ensure that kernel security mechanisms are
> functioning correctly.
I don't get it. How does TXT help kernel security mechanisms?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
On Fri, 26 Jun 2009, Pavel Machek wrote:
>
> > Also, hardware security measures such as TXT are important in providing
> > stronger mechanisms to ensure that kernel security mechanisms are
> > functioning correctly.
>
> I don't get it. How does TXT help kernel security mechanisms?
Kernel security mechanisms can be subverted and bypassed in the case of an
exploitable kernel vulnerability, or from exploitable buggy hardware (e.g.
which can access the entire host's memory via DMA). Attacks on kernel
security mechanisms have been describe in detail, see:
http://www.phrack.com/issues.html?issue=66&id=15#article
This is close to impossible to solve from within the kernel alone.
Hardware support is required to allow protection of the IO space (e.g. via
IOMMU/VT-d), and to allow verification of the kernel itself (via TXT).
A significant advance in this area is LKIM:
"Linux kernel integrity measurement using contextual inspection"
http://portal.acm.org/citation.cfm?id=1314354.1314362
(Unfortunately, the ACM has not made this freely available, although I
understand that individual authors are allowed to distribute their own
papers as they see fit).
- James
--
James Morris
<[email protected]>