[PATCHv3 17/17] x86: Introduce CONFIG_X86_INTEL_MKTME

Kirill A. Shutemov
2018-06-12T14:39:40Z

Add new config option to enabled/disable Multi-Key Total Memory
Encryption support.

MKTME uses MEMORY_PHYSICAL_PADDING to reserve enough space in per-KeyID
direct mappings for memory hotplug.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
arch/x86/Kconfig | 19 ++++++++++++++++++-
1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 4fa2cf807321..d013495bb4ae 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1513,6 +1513,23 @@ config ARCH_USE_MEMREMAP_PROT
def_bool y
depends on AMD_MEM_ENCRYPT

+config X86_INTEL_MKTME
+ bool "Intel Multi-Key Total Memory Encryption"
+ select DYNAMIC_PHYSICAL_MASK
+ select PAGE_EXTENSION
+ depends on X86_64 && CPU_SUP_INTEL
+ ---help---
+ Say yes to enable support for Multi-Key Total Memory Encryption.
+ This requires Intel processor that has support of the feature.
+
+ Multikey Total Memory Encryption (MKTME) is a technology that allows
+ transparent memory encryption in upcoming Intel platforms.
+
+ MKTME is built on top of TME. TME allows encryption of the entirety
+ of system memory using a single key. MKTME allows to have multiple
+ encryption domains, each having own key -- different memory pages can
+ be encrypted with different keys.
+
# Common NUMA Features
config NUMA
bool "Numa Memory Allocation and Scheduler Support"
@@ -2189,7 +2206,7 @@ config RANDOMIZE_MEMORY

config MEMORY_PHYSICAL_PADDING
hex "Physical memory mapping padding" if EXPERT
- depends on RANDOMIZE_MEMORY
+ depends on RANDOMIZE_MEMORY || X86_INTEL_MKTME
default "0xa" if MEMORY_HOTPLUG
default "0x0"
range 0x1 0x40 if MEMORY_HOTPLUG
--
2.17.1