x86/mm: Add support for early encryption/decryption of memory

Add support to be able to either encrypt or decrypt data in place during
the early stages of booting the kernel. This does not change the memory
encryption attribute - it is used for ensuring that data present in either
an encrypted or decrypted memory area is in the proper state (for example
the initrd will have been loaded by the boot loader and will not be
encrypted, but the memory that it resides in is marked as encrypted).

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Toshimitsu Kani <toshi.kani@hpe.com>
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/f9968e9432cd6c4b57ef245729be04ff18852225.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/x86/include/asm/mem_encrypt.h b/arch/x86/include/asm/mem_encrypt.h
index dbae7a5a347d8..8baa35ba2316c 100644
--- a/arch/x86/include/asm/mem_encrypt.h
+++ b/arch/x86/include/asm/mem_encrypt.h
@@ -21,6 +21,11 @@
 
 extern unsigned long sme_me_mask;
 
+void __init sme_early_encrypt(resource_size_t paddr,
+			      unsigned long size);
+void __init sme_early_decrypt(resource_size_t paddr,
+			      unsigned long size);
+
 void __init sme_early_init(void);
 
 void __init sme_encrypt_kernel(void);
@@ -30,6 +35,11 @@ void __init sme_enable(void);
 
 #define sme_me_mask	0UL
 
+static inline void __init sme_early_encrypt(resource_size_t paddr,
+					    unsigned long size) { }
+static inline void __init sme_early_decrypt(resource_size_t paddr,
+					    unsigned long size) { }
+
 static inline void __init sme_early_init(void) { }
 
 static inline void __init sme_encrypt_kernel(void) { }