x86, intel_txt: Intel TXT Sx shutdown support

Support for graceful handling of sleep states (S3/S4/S5) after an Intel(R) TXT launch.

Without this patch, attempting to place the system in one of the ACPI sleep
states (S3/S4/S5) will cause the TXT hardware to treat this as an attack and
will cause a system reset, with memory locked.  Not only may the subsequent
memory scrub take some time, but the platform will be unable to enter the
requested power state.

This patch calls back into the tboot so that it may properly and securely clean
up system state and clear the secrets-in-memory flag, after which it will place
the system into the requested sleep state using ACPI information passed by the kernel.

 arch/x86/kernel/smpboot.c     |    2 ++
 drivers/acpi/acpica/hwsleep.c |    3 +++
 kernel/cpu.c                  |    7 ++++++-
 3 files changed, 11 insertions(+), 1 deletion(-)

Signed-off-by: Joseph Cihula <joseph.cihula@intel.com>
Signed-off-by: Shane Wang <shane.wang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 2fecda69ee646a78402cc6a1d9e3d86a29ca06d6..61cc40887c48915707406dc5c2dbee04e5aac633 100644 (file)
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -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>
 
@@ -1317,6 +1318,7 @@ void play_dead_common(void)
 void native_play_dead(void)
 {
        play_dead_common();
+       tboot_shutdown(TB_SHUTDOWN_WFS);
        wbinvd_halt();
 }
 

diff --git a/drivers/acpi/acpica/hwsleep.c b/drivers/acpi/acpica/hwsleep.c
index db307a356f08b02edeb73597cc5893c1d3d45e9e..8c01dd3724e083a875210e7de357453efea6fc6d 100644 (file)
--- a/drivers/acpi/acpica/hwsleep.c
+++ b/drivers/acpi/acpica/hwsleep.c
@@ -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 +343,8 @@ acpi_status asmlinkage acpi_enter_sleep_state(u8 sleep_state)
 
        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);

diff --git a/kernel/cpu.c b/kernel/cpu.c
index 8ce10043e4aca1d9d48ab9f127e6079c8634f9fd..ff071e022a854b2ebea9f887174d09fde1522eb1 100644 (file)
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -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 */
@@ -376,7 +377,7 @@ 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)
@@ -391,6 +392,7 @@ 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);
@@ -401,6 +403,9 @@ int disable_nonboot_cpus(void)
                        break;
                }
        }
+       /* ensure all CPUs have gone into wait-for-SIPI */
+       error |= 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 */