x86, intel_txt: Intel TXT boot support

This patch adds kernel configuration and boot support for Intel Trusted
Execution Technology (Intel TXT).

Intel's technology for safer computing, Intel Trusted Execution
Technology (Intel 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.

A much more complete description of how these patches support TXT, how to
configure a system for it, etc. is in the Documentation/intel_txt.txt file
in this patch.

This patch provides the TXT support routines for complete functionality,
documentation for TXT support and for the changes to the boot_params structure,
and boot detection of a TXT launch.  Attempts to shutdown (reboot, Sx) the system
will result in platform resets; subsequent patches will support these shutdown modes
properly.

 Documentation/intel_txt.txt      |  210 +++++++++++++++++++++
 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     |  197 ++++++++++++++++++++
 arch/x86/kernel/Makefile         |    1
 arch/x86/kernel/setup.c          |    4
 arch/x86/kernel/tboot.c          |  379 +++++++++++++++++++++++++++++++++++++++
 security/Kconfig                 |   30 +++
 9 files changed, 827 insertions(+), 1 deletion(-)

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

1 files changed, 30 insertions, 0 deletions

diff --git a/security/Kconfig b/security/Kconfig
index d23c839038f0..edc7cbdc012a 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -113,6 +113,36 @@ config SECURITY_ROOTPLUG
 
           If you are unsure how to answer this question, answer N.
 
+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, which
+          helps to ensure that kernel security mechanisms are functioning
+          correctly. This level of protection requires a root of trust outside
+          of the kernel itself.
+
+          Intel TXT also helps solve real end user concerns about having
+          confidence that their hardware is running the VMM or kernel that
+          it was conigured with, especially since they may be responsible for
+          providing such assurances to VMs and services running on it.
+
+          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