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Kirill A. Shutemov 527a534c73 x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers
Secure Arbitration Mode (SEAM) is an extension of VMX architecture.  It
defines a new VMX root operation (SEAM VMX root) and a new VMX non-root
operation (SEAM VMX non-root) which are both isolated from the legacy
VMX operation where the host kernel runs.

A CPU-attested software module (called 'TDX module') runs in SEAM VMX
root to manage and protect VMs running in SEAM VMX non-root.  SEAM VMX
root is also used to host another CPU-attested software module (called
'P-SEAMLDR') to load and update the TDX module.

Host kernel transits to either P-SEAMLDR or TDX module via the new
SEAMCALL instruction, which is essentially a VMExit from VMX root mode
to SEAM VMX root mode.  SEAMCALLs are leaf functions defined by
P-SEAMLDR and TDX module around the new SEAMCALL instruction.

A guest kernel can also communicate with TDX module via TDCALL
instruction.

TDCALLs and SEAMCALLs use an ABI different from the x86-64 system-v ABI.
RAX is used to carry both the SEAMCALL leaf function number (input) and
the completion status (output).  Additional GPRs (RCX, RDX, R8-R11) may
be further used as both input and output operands in individual leaf.

TDCALL and SEAMCALL share the same ABI and require the largely same
code to pass down arguments and retrieve results.

Define an assembly macro that can be used to implement C wrapper for
both TDCALL and SEAMCALL.

Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20220405232939.73860-3-kirill.shutemov@linux.intel.com
2022-04-07 08:27:50 -07:00
arch x86/tdx: Provide common base for SEAMCALL and TDCALL C wrappers 2022-04-07 08:27:50 -07:00
block for-5.18/block-2022-04-01 2022-04-01 16:20:00 -07:00
certs Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
crypto for-5.18/64bit-pi-2022-03-25 2022-03-26 12:01:35 -07:00
Documentation Updates to Tracing: 2022-04-03 12:26:01 -07:00
drivers A single revert to fix a boot regression seen when clk_put() started 2022-04-03 12:21:14 -07:00
fs Updates to Tracing: 2022-04-03 12:26:01 -07:00
include Updates to Tracing: 2022-04-03 12:26:01 -07:00
init Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
ipc fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
kernel Updates to Tracing: 2022-04-03 12:26:01 -07:00
lib for-5.18/block-2022-04-01 2022-04-01 16:20:00 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Filesystem/VFS changes for 5.18, part two 2022-04-01 13:50:50 -07:00
net Networking fixes for 5.18-rc1 and rethook patches. 2022-03-31 11:23:31 -07:00
samples dma-mapping updates for Linux 5.18 2022-03-29 08:50:14 -07:00
scripts modpost: restore the warning message for missing symbol versions 2022-04-03 03:11:51 +09:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound sound fixes for 5.18-rc1 2022-04-01 10:32:46 -07:00
tools A set of x86 fixes and updates: 2022-04-03 12:15:47 -07:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt KVM: Remove dirty handling from gfn_to_pfn_cache completely 2022-04-02 05:34:41 -04:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update Kirill's email 2022-04-01 11:46:09 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS chrome platform changes for 5.18 2022-04-02 10:44:18 -07:00
Makefile Linux 5.18-rc1 2022-04-03 14:08:21 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.