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....@intel.com> Signed-off-by: Xiaoyan Zhang <xiaoyan.zh...@intel.com> Signed-off-by: Gang Wei <gang....@intel.com> --- 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....@intel.com> 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....@intel.com> +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....@intel.com> +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....@intel.com> +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....@intel.com> +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....@intel.com> +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....@intel.com> +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....@intel.com> +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....@intel.com> +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....@intel.com> +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 ac889f7..256fbde 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/