Commit 0c7180f2 authored by Changbin Du's avatar Changbin Du Committed by Jonathan Corbet

Documentation: x86: convert amd-memory-encryption.txt to reST

This converts the plain text documentation to reStructuredText format and
add it to Sphinx TOC tree. No essential content change.
Signed-off-by: default avatarChangbin Du <changbin.du@gmail.com>
Reviewed-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent f10b07a0
.. SPDX-License-Identifier: GPL-2.0
=====================
AMD Memory Encryption
=====================
Secure Memory Encryption (SME) and Secure Encrypted Virtualization (SEV) are
features found on AMD processors.
......@@ -34,7 +40,7 @@ is operating in 64-bit or 32-bit PAE mode, in all other modes the SEV hardware
forces the memory encryption bit to 1.
Support for SME and SEV can be determined through the CPUID instruction. The
CPUID function 0x8000001f reports information related to SME:
CPUID function 0x8000001f reports information related to SME::
0x8000001f[eax]:
Bit[0] indicates support for SME
......@@ -48,14 +54,14 @@ CPUID function 0x8000001f reports information related to SME:
addresses)
If support for SME is present, MSR 0xc00100010 (MSR_K8_SYSCFG) can be used to
determine if SME is enabled and/or to enable memory encryption:
determine if SME is enabled and/or to enable memory encryption::
0xc0010010:
Bit[23] 0 = memory encryption features are disabled
1 = memory encryption features are enabled
If SEV is supported, MSR 0xc0010131 (MSR_AMD64_SEV) can be used to determine if
SEV is active:
SEV is active::
0xc0010131:
Bit[0] 0 = memory encryption is not active
......@@ -68,6 +74,7 @@ requirements for the system. If this bit is not set upon Linux startup then
Linux itself will not set it and memory encryption will not be possible.
The state of SME in the Linux kernel can be documented as follows:
- Supported:
The CPU supports SME (determined through CPUID instruction).
......
......@@ -20,3 +20,4 @@ x86-specific Documentation
pat
protection-keys
intel_mpx
amd-memory-encryption
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