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SubjectRe: [RFC PATCH v2 07/20] x86: Provide general kernel support for memory encryption
On Mon, Aug 22, 2016 at 05:36:46PM -0500, Tom Lendacky wrote:
> Adding general kernel support for memory encryption includes:
> - Modify and create some page table macros to include the Secure Memory
> Encryption (SME) memory encryption mask
> - Update kernel boot support to call an SME routine that checks for and
> sets the SME capability (the SME routine will grow later and for now
> is just a stub routine)
> - Update kernel boot support to call an SME routine that encrypts the
> kernel (the SME routine will grow later and for now is just a stub
> routine)
> - Provide an SME initialization routine to update the protection map with
> the memory encryption mask so that it is used by default
>
> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>

...

> diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
> index c98a559..30f7715 100644
> --- a/arch/x86/kernel/head_64.S
> +++ b/arch/x86/kernel/head_64.S
> @@ -95,6 +95,13 @@ startup_64:
> jnz bad_address
>
> /*
> + * Enable memory encryption (if available). Add the memory encryption
> + * mask to %rbp to include it in the the page table fixup.
> + */
> + call sme_enable
> + addq sme_me_mask(%rip), %rbp
> +
> + /*
> * Fixup the physical addresses in the page table
> */
> addq %rbp, early_level4_pgt + (L4_START_KERNEL*8)(%rip)
> @@ -116,7 +123,8 @@ startup_64:
> movq %rdi, %rax
> shrq $PGDIR_SHIFT, %rax
>
> - leaq (4096 + _KERNPG_TABLE)(%rbx), %rdx
> + leaq (4096 + __KERNPG_TABLE)(%rbx), %rdx
> + addq sme_me_mask(%rip), %rdx /* Apply mem encryption mask */

Please add comments over the line and not at the side...

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.

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