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From:   "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To:     Ingo Molnar <mingo@redhat.com>, x86@kernel.org,
        Thomas Gleixner <tglx@linutronix.de>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Tom Lendacky <thomas.lendacky@amd.com>
Cc:     Dave Hansen <dave.hansen@intel.com>,
        Kai Huang <kai.huang@linux.intel.com>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCHv5 19/19] x86: Introduce CONFIG_X86_INTEL_MKTME
Date:   Tue, 17 Jul 2018 14:20:29 +0300
Message-Id: <20180717112029.42378-20-kirill.shutemov@linux.intel.com>
In-Reply-To: <20180717112029.42378-1-kirill.shutemov@linux.intel.com>
References: <20180717112029.42378-1-kirill.shutemov@linux.intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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 b6f1785c2176..023a22568c06 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1523,6 +1523,23 @@ 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 an 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 having 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"
@@ -2199,7 +2216,7 @@ 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
-- 
2.18.0