On 6/20/2017 2:38 AM, Borislav Petkov wrote:
> On Fri, Jun 16, 2017 at 01:51:15PM -0500, Tom Lendacky wrote:
>> Add support to the early boot code to use Secure Memory Encryption (SME).
>> Since the kernel has been loaded into memory in a decrypted state, encrypt
>> the kernel in place and update the early pagetables with the memory
>> encryption mask so that new pagetable entries will use memory encryption.
>>
>> The routines to set the encryption mask and perform the encryption are
>> stub routines for now with functionality to be added in a later patch.
>>
>> Because of the need to have the routines available to head_64.S, the
>> mem_encrypt.c is always built and #ifdefs in mem_encrypt.c will provide
>> functionality or stub routines depending on CONFIG_AMD_MEM_ENCRYPT.
>>
>> Signed-off-by: Tom Lendacky <thomas.lendacky at amd.com>
>> ---
>> arch/x86/include/asm/mem_encrypt.h | 8 +++++++
>> arch/x86/kernel/head64.c | 33 +++++++++++++++++++++---------
>> arch/x86/kernel/head_64.S | 39 ++++++++++++++++++++++++++++++++++--
>> arch/x86/mm/Makefile | 4 +---
>> arch/x86/mm/mem_encrypt.c | 24 ++++++++++++++++++++++
>> 5 files changed, 93 insertions(+), 15 deletions(-)
>
> ...
>
>> diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
>> index b99d469..9a78277 100644
>> --- a/arch/x86/mm/mem_encrypt.c
>> +++ b/arch/x86/mm/mem_encrypt.c
>> @@ -11,6 +11,9 @@
>> */
>>
>> #include <linux/linkage.h>
>> +#include <linux/init.h>
>> +
>> +#ifdef CONFIG_AMD_MEM_ENCRYPT
>>
>> /*
>> * Since SME related variables are set early in the boot process they must
>> @@ -19,3 +22,24 @@
>> */
>> unsigned long sme_me_mask __section(.data) = 0;
>> EXPORT_SYMBOL_GPL(sme_me_mask);
>> +
>> +void __init sme_encrypt_kernel(void)
>> +{
>> +}
>
> Just the minor:
>
> void __init sme_encrypt_kernel(void) { }
>
> in case you have to respin.
I have to re-spin for the kbuild test error. But given that this
function will be filled in later it's probably not worth doing the
space savings here.
Thanks,
Tom
>
> Reviewed-by: Borislav Petkov <bp at suse.de>
>
