Safer Mode Extensions (SMX) provide a programming interface for
system software to establish a measured environment within the
platform to support trust decisions by end users.
We need enable SMX operation by setting CR4.SMXE[Bit 14] = 1,
if system has txt supported and lives in messured environment.
Signed-off-by: Qiaowei Ren <[email protected]>
---
arch/x86/include/uapi/asm/processor-flags.h | 1 +
arch/x86/kernel/tboot.c | 100 ++++++++++++++-------------
2 files changed, 53 insertions(+), 48 deletions(-)
diff --git a/arch/x86/include/uapi/asm/processor-flags.h b/arch/x86/include/uapi/asm/processor-flags.h
index 54991a7..9edd51f 100644
--- a/arch/x86/include/uapi/asm/processor-flags.h
+++ b/arch/x86/include/uapi/asm/processor-flags.h
@@ -61,6 +61,7 @@
#define X86_CR4_OSFXSR 0x00000200 /* enable fast FPU save and restore */
#define X86_CR4_OSXMMEXCPT 0x00000400 /* enable unmasked SSE exceptions */
#define X86_CR4_VMXE 0x00002000 /* enable VMX virtualization */
+#define X86_CR4_SMXE 0x00004000 /* enable SMX operation */
#define X86_CR4_RDWRGSFS 0x00010000 /* enable RDWRGSFS support */
#define X86_CR4_PCIDE 0x00020000 /* enable PCID support */
#define X86_CR4_OSXSAVE 0x00040000 /* enable xsave and xrestore */
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index f84fe00..184c546 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -58,51 +58,6 @@ EXPORT_SYMBOL(tboot);
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,
@@ -329,6 +284,10 @@ static int __cpuinit tboot_cpu_callback(struct notifier_block *nfb,
if (tboot_wait_for_aps(atomic_read(&ap_wfs_count)))
return NOTIFY_BAD;
break;
+
+ case CPU_STARTING:
+ set_in_cr4(X86_CR4_SMXE);
+ break;
}
return NOTIFY_OK;
}
@@ -338,6 +297,54 @@ static struct notifier_block tboot_cpu_notifier __cpuinitdata =
.notifier_call = tboot_cpu_callback,
};
+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_warn("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_warn("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_warn("tboot at 0x%llx is invalid\n",
+ boot_params.tboot_addr);
+ tboot = NULL;
+ return;
+ }
+ if (tboot->version < 5) {
+ pr_warn("tboot version is invalid: %u\n", tboot->version);
+ tboot = NULL;
+ return;
+ }
+
+ atomic_set(&ap_wfs_count, 0);
+ register_cpu_notifier(&tboot_cpu_notifier);
+
+ 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 __init int tboot_late_init(void)
{
if (!tboot_enabled())
@@ -345,9 +352,6 @@ static __init int tboot_late_init(void)
tboot_create_trampoline();
- atomic_set(&ap_wfs_count, 0);
- register_hotcpu_notifier(&tboot_cpu_notifier);
-
acpi_os_set_prepare_sleep(&tboot_sleep);
return 0;
}
--
1.7.9.5