docs: x86: move two x86-specific files to x86 arch dir

Those two docs belong to the x86 architecture:

   Documentation/Intel-IOMMU.txt -> Documentation/x86/intel-iommu.rst
   Documentation/intel_txt.txt -> Documentation/x86/intel_txt.rst

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

1 files changed, 0 insertions, 227 deletions

diff --git a/Documentation/intel_txt.txt b/Documentation/intel_txt.txt
deleted file mode 100644
index d83c1a2122c9..000000000000
--- a/Documentation/intel_txt.txt
+++ /dev/null
@@ -1,227 +0,0 @@
-=====================
-Intel(R) TXT Overview
-=====================
-
-Intel's technology for safer computing, Intel(R) Trusted Execution
-Technology (Intel(R) 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:
-
--  Provides dynamic root of trust for measurement (DRTM)
--  Data protection in case of improper shutdown
--  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.
-
-Intel TXT has been presented at various events over the past few
-years, some of which are:
-
-      - LinuxTAG 2008:
-          http://www.linuxtag.org/2008/en/conf/events/vp-donnerstag.html
-
-      - TRUST2008:
-          http://www.trust-conference.eu/downloads/Keynote-Speakers/
-          3_David-Grawrock_The-Front-Door-of-Trusted-Computing.pdf
-
-      - IDF, Shanghai:
-          http://www.prcidf.com.cn/index_en.html
-
-      - IDFs 2006, 2007
-	  (I'm not sure if/where they are online)
-
-Trusted Boot Project Overview
-=============================
-
-Trusted Boot (tboot) is an open source, pre-kernel/VMM module that
-uses Intel TXT to perform a measured and verified launch of an OS
-kernel/VMM.
-
-It is hosted on SourceForge at http://sourceforge.net/projects/tboot.
-The mercurial source repo is available at http://www.bughost.org/
-repos.hg/tboot.hg.
-
-Tboot currently supports launching Xen (open source VMM/hypervisor
-w/ TXT support since v3.2), and now Linux kernels.
-
-
-Value Proposition for Linux or "Why should you care?"
-=====================================================
-
-While there are many products and technologies that attempt to
-measure or protect the integrity of a running kernel, they all
-assume the kernel is "good" to begin with.  The Integrity
-Measurement Architecture (IMA) and Linux Integrity Module interface
-are examples of such solutions.
-
-To get trust in the initial kernel without using Intel TXT, a
-static root of trust must be used.  This bases trust in BIOS
-starting at system reset and requires measurement of all code
-executed between system reset through the completion of the kernel
-boot as well as data objects used by that code.  In the case of a
-Linux kernel, this means all of BIOS, any option ROMs, the
-bootloader and the boot config.  In practice, this is a lot of
-code/data, much of which is subject to change from boot to boot
-(e.g. changing NICs may change option ROMs).  Without reference
-hashes, these measurement changes are difficult to assess or
-confirm as benign.  This process also does not provide DMA
-protection, memory configuration/alias checks and locks, crash
-protection, or policy support.
-
-By using the hardware-based root of trust that Intel TXT provides,
-many of these issues can be mitigated.  Specifically: many
-pre-launch components can be removed from the trust chain, DMA
-protection is provided to all launched components, a large number
-of platform configuration checks are performed and values locked,
-protection is provided for any data in the event of an improper
-shutdown, and there is support for policy-based execution/verification.
-This provides a more stable measurement and a higher assurance of
-system configuration and initial state than would be otherwise
-possible.  Since the tboot project is open source, source code for
-almost all parts of the trust chain is available (excepting SMM and
-Intel-provided firmware).
-
-How Does it Work?
-=================
-
--  Tboot is an executable that is launched by the bootloader as
-   the "kernel" (the binary the bootloader executes).
--  It performs all of the work necessary to determine if the
-   platform supports Intel TXT and, if so, executes the GETSEC[SENTER]
-   processor instruction that initiates the dynamic root of trust.
-
-   -  If tboot determines that the system does not support Intel TXT
-      or is not configured correctly (e.g. the SINIT AC Module was
-      incorrect), it will directly launch the kernel with no changes
-      to any state.
-   -  Tboot will output various information about its progress to the
-      terminal, serial port, and/or an in-memory log; the output
-      locations can be configured with a command line switch.
-
--  The GETSEC[SENTER] instruction will return control to tboot and
-   tboot then verifies certain aspects of the environment (e.g. TPM NV
-   lock, e820 table does not have invalid entries, etc.).
--  It will wake the APs from the special sleep state the GETSEC[SENTER]
-   instruction had put them in and place them into a wait-for-SIPI
-   state.
-
-   -  Because the processors will not respond to an INIT or SIPI when
-      in the TXT environment, it is necessary to create a small VT-x
-      guest for the APs.  When they run in this guest, they will
-      simply wait for the INIT-SIPI-SIPI sequence, which will cause
-      VMEXITs, and then disable VT and jump to the SIPI vector.  This
-      approach seemed like a better choice than having to insert
-      special code into the kernel's MP wakeup sequence.
-
--  Tboot then applies an (optional) user-defined launch policy to
-   verify the kernel and initrd.
-
-   -  This policy is rooted in TPM NV and is described in the tboot
-      project.  The tboot project also contains code for tools to
-      create and provision the policy.
-   -  Policies are completely under user control and if not present
-      then any kernel will be launched.
-   -  Policy action is flexible and can include halting on failures
-      or simply logging them and continuing.
-
--  Tboot adjusts the e820 table provided by the bootloader to reserve
-   its own location in memory as well as to reserve certain other
-   TXT-related regions.
--  As part of its launch, tboot DMA protects all of RAM (using the
-   VT-d PMRs).  Thus, the kernel must be booted with 'intel_iommu=on'
-   in order to remove this blanket protection and use VT-d's
-   page-level protection.
--  Tboot will populate a shared page with some data about itself and
-   pass this to the Linux kernel as it transfers control.
-
-   -  The location of the shared page is passed via the boot_params
-      struct as a physical address.
-
--  The kernel will look for the tboot shared page address and, if it
-   exists, map it.
--  As one of the checks/protections provided by TXT, it makes a copy
-   of the VT-d DMARs in a DMA-protected region of memory and verifies
-   them for correctness.  The VT-d code will detect if the kernel was
-   launched with tboot and use this copy instead of the one in the
-   ACPI table.
--  At this point, tboot and TXT are out of the picture until a
-   shutdown (S<n>)
--  In order to put a system into any of the sleep states after a TXT
-   launch, TXT must first be exited.  This is to prevent attacks that
-   attempt to crash the system to gain control on reboot and steal
-   data left in memory.
-
-   -  The kernel will perform all of its sleep preparation and
-      populate the shared page with the ACPI data needed to put the
-      platform in the desired sleep state.
-   -  Then the kernel jumps into tboot via the vector specified in the
-      shared page.
-   -  Tboot will clean up the environment and disable TXT, then use the
-      kernel-provided ACPI information to actually place the platform
-      into the desired sleep state.
-   -  In the case of S3, tboot will also register itself as the resume
-      vector.  This is necessary because it must re-establish the
-      measured environment upon resume.  Once the TXT environment
-      has been restored, it will restore the TPM PCRs and then
-      transfer control back to the kernel's S3 resume vector.
-      In order to preserve system integrity across S3, the kernel
-      provides tboot with a set of memory ranges (RAM and RESERVED_KERN
-      in the e820 table, but not any memory that BIOS might alter over
-      the S3 transition) that tboot will calculate a MAC (message
-      authentication code) over and then seal with the TPM. On resume
-      and once the measured environment has been re-established, tboot
-      will re-calculate the MAC and verify it against the sealed value.
-      Tboot's policy determines what happens if the verification fails.
-      Note that the c/s 194 of tboot which has the new MAC code supports
-      this.
-
-That's pretty much it for TXT support.
-
-
-Configuring the System
-======================
-
-This code works with 32bit, 32bit PAE, and 64bit (x86_64) kernels.
-
-In BIOS, the user must enable:  TPM, TXT, VT-x, VT-d.  Not all BIOSes
-allow these to be individually enabled/disabled and the screens in
-which to find them are BIOS-specific.
-
-grub.conf needs to be modified as follows::
-
-        title Linux 2.6.29-tip w/ tboot
-          root (hd0,0)
-                kernel /tboot.gz logging=serial,vga,memory
-                module /vmlinuz-2.6.29-tip intel_iommu=on ro
-                       root=LABEL=/ rhgb console=ttyS0,115200 3
-                module /initrd-2.6.29-tip.img
-                module /Q35_SINIT_17.BIN
-
-The kernel option for enabling Intel TXT support is found under the
-Security top-level menu and is called "Enable Intel(R) Trusted
-Execution Technology (TXT)".  It is considered EXPERIMENTAL and
-depends on the generic x86 support (to allow maximum flexibility in
-kernel build options), since the tboot code will detect whether the
-platform actually supports Intel TXT and thus whether any of the
-kernel code is executed.
-
-The Q35_SINIT_17.BIN file is what Intel TXT refers to as an
-Authenticated Code Module.  It is specific to the chipset in the
-system and can also be found on the Trusted Boot site.  It is an
-(unencrypted) module signed by Intel that is used as part of the
-DRTM process to verify and configure the system.  It is signed
-because it operates at a higher privilege level in the system than
-any other macrocode and its correct operation is critical to the
-establishment of the DRTM.  The process for determining the correct
-SINIT ACM for a system is documented in the SINIT-guide.txt file
-that is on the tboot SourceForge site under the SINIT ACM downloads.