These interfaces are located in /sys/devices/platform/intel_txt/parameter/,
showing specific parameter information for SMX features supported by
the processor.
Safer Mode Extensions (SMX) provide a processor's programming
interface in an Intel TXT platform for system software to establish
a measured environment within the platform to support trust decisions
by end users.
Signed-off-by: Qiaowei Ren <qiaowei.ren@xxxxxxxxx>
Signed-off-by: Xiaoyan Zhang <xiaoyan.zhang@xxxxxxxxx>
Signed-off-by: Gang Wei <gang.wei@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-platform-intel-txt | 73 ++++++
drivers/platform/x86/intel_txt/Makefile | 2 +-
drivers/platform/x86/intel_txt/txt-parameter.c | 254 ++++++++++++++++++++
drivers/platform/x86/intel_txt/txt-parameter.h | 39 +++
drivers/platform/x86/intel_txt/txt-sysfs.c | 5 +
5 files changed, 372 insertions(+), 1 deletion(-)
create mode 100644 drivers/platform/x86/intel_txt/txt-parameter.c
create mode 100644 drivers/platform/x86/intel_txt/txt-parameter.h
diff --git a/Documentation/ABI/testing/sysfs-platform-intel-txt b/Documentation/ABI/testing/sysfs-platform-intel-txt
index fa20a9f..b445f5d 100644
--- a/Documentation/ABI/testing/sysfs-platform-intel-txt
+++ b/Documentation/ABI/testing/sysfs-platform-intel-txt
@@ -307,3 +307,76 @@ Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
Description: 0 = Chipset acknowledges that no secrets are in memory.
1 = Chipset believes that secrets are in memory and will
provide reset protection.
+
+What: /sys/devices/platform/intel_txt/parameter/
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The parameter/ directory exposes specific parameter
+ information for SMX features supported by the processor.
+
+ Safer Mode Extensions (SMX) provide a processor's
+ programming interface in an Intel TXT platform for
+ system software to establish a measured environment
+ within the platform to support trust decisions by
+ end users.
+
+What: /sys/devices/platform/intel_txt/parameter/acm_max_size
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "acm_max_size" property will show max size of
+ authenticated code execution area.
+
+What: /sys/devices/platform/intel_txt/parameter/acm_mem_types
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "acm_max_types" property will show supportable memory
+ types for memory mapped outside of the authenticated code
+ execution area.
+
+What: /sys/devices/platform/intel_txt/parameter/senter_controls
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "senter_controls" property will show selective SENTER
+ functionality control.
+
+What: /sys/devices/platform/intel_txt/parameter/preserve_mce
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "preserve_mce" property produces a '1' if machine
+ check status registers can be preserved through ENTERACCS
+ and SENTER.
+
+What: /sys/devices/platform/intel_txt/parameter/proc_based_scrtm
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "proc_based_scrtm" property produces a '1' if this
+ processor implements a processorrooted S-CRTM capability
+ and '0' if not (S-CRTM is rooted in BIOS).
+
+What: /sys/devices/platform/intel_txt/parameter/n_versions
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "n_versions" property will show AC module version
+ numbers supported.
+
+What: /sys/devices/platform/intel_txt/parameter/acm_version
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "acm_version" property will output supported AC
+ module version, including version comparison mask and
+ version index.
+
+What: /sys/devices/platform/intel_txt/parameter/acm_version_index
+Date: May 2013
+KernelVersion: 3.9
+Contact: "Qiaowei Ren" <qiaowei.ren@xxxxxxxxx>
+Description: The "acm_version_index" property allows you to set the
+ version index for output.
diff --git a/drivers/platform/x86/intel_txt/Makefile b/drivers/platform/x86/intel_txt/Makefile
index 8d5258e..8370582 100644
--- a/drivers/platform/x86/intel_txt/Makefile
+++ b/drivers/platform/x86/intel_txt/Makefile
@@ -2,4 +2,4 @@
# Makefile for the intel TXT drivers.
#
obj-$(CONFIG_INTEL_TXT_DRIVER) += intel_txt.o
-intel_txt-y := txt-sysfs.o txt-config.o
+intel_txt-y := txt-sysfs.o txt-config.o txt-parameter.o
diff --git a/drivers/platform/x86/intel_txt/txt-parameter.c b/drivers/platform/x86/intel_txt/txt-parameter.c
new file mode 100644
index 0000000..a0073bf
--- /dev/null
+++ b/drivers/platform/x86/intel_txt/txt-parameter.c
@@ -0,0 +1,254 @@
+/*
+ * txt-parameter.c
+ *
+ * specific parameter information for SMX features supported by the processor.
+ *
+ * Safer Mode Extensions (SMX) provide a processor's programming
+ * interface in an Intel TXT platform for system software to establish
+ * a measured environment within the platform to support trust decisions
+ * by end users.
+ *
+ * - parameter/
+ * n_versions -r--r--r--;
+ * acm_max_size -r--r--r--;
+ * acm_mem_types -r--r--r--;
+ * senter_controls -r--r--r--;
+ * proc_based_scrtm -r--r--r--;
+ * preserve_mce -r--r--r--;
+ * acm_version_index -rw-rw-r--; desginate which acm_version will be output
+ * acm_version -r--r--r--;
+ */
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+
+#include "txt-parameter.h"
+
+static u32 acm_version_index;
+
+static void __getsec_parameters(uint32_t index, int *param_type,
+ uint32_t *peax, uint32_t *pebx,
+ uint32_t *pecx)
+{
+ uint32_t eax, ebx, ecx;
+
+ __asm__ __volatile__ ("getsec"
+ : "=a"(eax), "=b"(ebx), "=c"(ecx)
+ : "a"(IA32_GETSEC_PARAMETERS), "b"(index));
+
+ *param_type = eax & 0x1f;
+ *peax = eax;
+ *pebx = ebx;
+ *pecx = ecx;
+}
+
+static bool get_parameters(struct getsec_parameters *params)
+{
+ uint32_t index, eax, ebx, ecx;
+ int param_type;
+
+ memset(params, 0, sizeof(struct getsec_parameters));
+ params->acm_max_size = DEF_ACM_MAX_SIZE;
+ params->acm_mem_types = DEF_ACM_MEM_TYPES;
+ params->senter_controls = DEF_SENTER_CTRLS;
+ params->proc_based_scrtm = false;
+ params->preserve_mce = false;
+
+ index = 0;
+ do {
+ __getsec_parameters(index++, ¶m_type, &eax, &ebx, &ecx);
+
+ switch (param_type) {
+ case 1:
+ if (params->n_versions == MAX_SUPPORTED_ACM_VERSIONS)
+ continue;
+ params->acm_versions[params->n_versions].mask = ebx;
+ params->acm_versions[params->n_versions].version = ecx;
+ params->n_versions++;
+ break;
+
+ case 2:
+ params->acm_max_size = eax & 0xffffffe0;
+ break;
+
+ case 3:
+ params->acm_mem_types = eax & 0xffffffe0;
+ break;
+
+ case 4:
+ params->senter_controls = (eax & 0x00007fff) >> 8;
+ break;
+
+ case 5:
+ params->proc_based_scrtm =
+ (eax & 0x00000020) ? true : false;
+ params->preserve_mce =
+ (eax & 0x00000040) ? true : false;
+ break;
+
+ default:
+ param_type = 0;
+ break;
+ }
+ } while (param_type != 0);
+
+ if (params->n_versions == 0) {
+ params->acm_versions[0].mask = DEF_ACM_VER_MASK;
+ params->acm_versions[0].version = DEF_ACM_VER_SUPPORTED;
+ params->n_versions = 1;
+ }
+
+ return true;
+}
+
+static ssize_t show_param(char *buf, u32 index)
+{
+ struct getsec_parameters params;
+
+ if (!get_parameters(¶ms))
+ return -EPERM;
+
+ switch (index) {
+ case off_n_versions:
+ return scnprintf(buf, PAGE_SIZE, "%d\n",
+ params.n_versions);
+
+ case off_acm_max_size:
+ return scnprintf(buf, PAGE_SIZE, "%u\n",
+ params.acm_max_size);
+
+ case off_acm_mem_types:
+ return scnprintf(buf, PAGE_SIZE, "%u\n",
+ params.acm_mem_types);
+
+ case off_senter_controls:
+ return scnprintf(buf, PAGE_SIZE, "%u\n",
+ params.senter_controls);
+
+ case off_proc_based_scrtm:
+ return scnprintf(buf, PAGE_SIZE, "%d\n",
+ params.proc_based_scrtm);
+
+ case off_preserve_mce:
+ return scnprintf(buf, PAGE_SIZE, "%d\n",
+ params.preserve_mce);
+
+ case off_acm_version:
+ return scnprintf(buf, PAGE_SIZE,
+ "mask: %u\nversion: %u\n",
+ params.acm_versions[acm_version_index].mask,
+ params.acm_versions[acm_version_index].version);
+
+ default:
+ return -EINVAL;
+ }
+}
+
+ssize_t txt_show_param_nversions(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return show_param(buf, off_n_versions);
+}
+static DEVICE_ATTR(n_versions, S_IRUGO, txt_show_param_nversions, NULL);
+
+ssize_t txt_show_param_acmmaxsize(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return show_param(buf, off_acm_max_size);
+}
+static DEVICE_ATTR(acm_max_size, S_IRUGO, txt_show_param_acmmaxsize, NULL);
+
+ssize_t txt_show_param_acmmemtypes(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return show_param(buf, off_acm_mem_types);
+}
+static DEVICE_ATTR(acm_mem_types, S_IRUGO, txt_show_param_acmmemtypes, NULL);
+
+ssize_t txt_show_param_senter(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return show_param(buf, off_senter_controls);
+}
+static DEVICE_ATTR(senter_controls, S_IRUGO, txt_show_param_senter, NULL);
+
+ssize_t txt_show_param_proc(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return show_param(buf, off_proc_based_scrtm);
+}
+static DEVICE_ATTR(proc_based_scrtm, S_IRUGO, txt_show_param_proc, NULL);
+
+ssize_t txt_show_param_preserve(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return show_param(buf, off_preserve_mce);
+}
+static DEVICE_ATTR(preserve_mce, S_IRUGO, txt_show_param_preserve, NULL);
+
+ssize_t txt_show_param_acmvindex(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return scnprintf(buf, PAGE_SIZE, "%d\n", acm_version_index);
+}
+
+ssize_t txt_store_param_acmvindex(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ u32 index;
+ struct getsec_parameters params;
+
+ if (sscanf(buf, "%d", &index) != 1)
+ return -EINVAL;
+
+ if (!get_parameters(¶ms))
+ return -EPERM;
+
+ if (index >= params.n_versions)
+ return -EINVAL;
+
+ acm_version_index = index;
+
+ return count;
+}
+static DEVICE_ATTR(acm_version_index, S_IRUGO | S_IWUSR | S_IWGRP,
+ txt_show_param_acmvindex, txt_store_param_acmvindex);
+
+ssize_t txt_show_param_acmversion(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return show_param(buf, off_acm_version);
+}
+static DEVICE_ATTR(acm_version, S_IRUGO, txt_show_param_acmversion, NULL);
+
+static struct attribute *param_attrs[] = {
+ &dev_attr_n_versions.attr,
+ &dev_attr_acm_max_size.attr,
+ &dev_attr_acm_mem_types.attr,
+ &dev_attr_senter_controls.attr,
+ &dev_attr_proc_based_scrtm.attr,
+ &dev_attr_preserve_mce.attr,
+ &dev_attr_acm_version_index.attr,
+ &dev_attr_acm_version.attr,
+ NULL,
+};
+
+static struct attribute_group param_attr_grp = {
+ .name = "parameter",
+ .attrs = param_attrs
+};
+
+int sysfs_create_parameter(struct kobject *parent)
+{
+ return sysfs_create_group(parent, ¶m_attr_grp);
+}
+
diff --git a/drivers/platform/x86/intel_txt/txt-parameter.h b/drivers/platform/x86/intel_txt/txt-parameter.h
new file mode 100644
index 0000000..55b232b
--- /dev/null
+++ b/drivers/platform/x86/intel_txt/txt-parameter.h
@@ -0,0 +1,39 @@
+#ifndef __PARAMETER_H__
+#define __PARAMETER_H__
+
+#define CR4_SMXE 0x00004000
+#define MAX_SUPPORTED_ACM_VERSIONS 16
+
+#define DEF_ACM_MAX_SIZE 0x8000
+#define DEF_ACM_VER_MASK 0xffffffff
+#define DEF_ACM_VER_SUPPORTED 0x00
+#define DEF_ACM_MEM_TYPES 0x0100
+#define DEF_SENTER_CTRLS 0x00
+
+#define IA32_GETSEC_PARAMETERS 6
+
+#define off_n_versions 1
+#define off_acm_max_size 2
+#define off_acm_mem_types 3
+#define off_senter_controls 4
+#define off_proc_based_scrtm 5
+#define off_preserve_mce 6
+#define off_acm_version 7
+
+typedef struct getsec_parameters {
+ struct {
+ uint32_t mask;
+ uint32_t version;
+ } acm_versions[MAX_SUPPORTED_ACM_VERSIONS];
+ int n_versions;
+ uint32_t acm_max_size;
+ uint32_t acm_mem_types;
+ uint32_t senter_controls;
+ bool proc_based_scrtm;
+ bool preserve_mce;
+} getsec_parameters_t;
+
+extern int sysfs_create_parameter(struct kobject *parent);
+
+#endif /* __PARAMETER_H__ */
+
diff --git a/drivers/platform/x86/intel_txt/txt-sysfs.c b/drivers/platform/x86/intel_txt/txt-sysfs.c
index 4837935..9884618 100644
--- a/drivers/platform/x86/intel_txt/txt-sysfs.c
+++ b/drivers/platform/x86/intel_txt/txt-sysfs.c
@@ -37,6 +37,7 @@
#include <linux/tboot.h>
#include "txt-config.h"
+#include "txt-parameter.h"
#define DEV_NAME "intel_txt"
static struct platform_device *txt_pdev;
@@ -56,6 +57,10 @@ static int __init txt_sysfs_init(void)
if (retval)
goto err;
+ retval = sysfs_create_parameter(&txt_pdev->dev.kobj);
+ if (retval)
+ goto err;
+
return 0;
err:
--
1.7.9.5
--
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