Hi!
> This patch adds the support to check for and enable SME when available
> on the processor and when the mem_encrypt=on command line option is set.
> This consists of setting the encryption mask, calculating the number of
> physical bits of addressing lost and encrypting the kernel "in place."
>
> Signed-off-by: Tom Lendacky <thomas.lenda...@amd.com>
> ---
> Documentation/kernel-parameters.txt | 3
> arch/x86/kernel/asm-offsets.c | 2
> arch/x86/kernel/mem_encrypt.S | 306
> +++++++++++++++++++++++++++++++++++
> 3 files changed, 311 insertions(+)
>
> diff --git a/arch/x86/kernel/mem_encrypt.S b/arch/x86/kernel/mem_encrypt.S
> index f2e0536..4d3326d 100644
> --- a/arch/x86/kernel/mem_encrypt.S
> +++ b/arch/x86/kernel/mem_encrypt.S
> @@ -12,13 +12,236 @@
>
> #include <linux/linkage.h>
>
> +#include <asm/processor-flags.h>
> +#include <asm/pgtable.h>
> +#include <asm/page.h>
> +#include <asm/msr.h>
> +#include <asm/asm-offsets.h>
> +
> .text
> .code64
> ENTRY(sme_enable)
> +#ifdef CONFIG_AMD_MEM_ENCRYPT
> + /* Check for AMD processor */
> + xorl %eax, %eax
> + cpuid
> + cmpl $0x68747541, %ebx # AuthenticAMD
> + jne .Lno_mem_encrypt
> + cmpl $0x69746e65, %edx
> + jne .Lno_mem_encrypt
> + cmpl $0x444d4163, %ecx
> + jne .Lno_mem_encrypt
> +
> + /* Check for memory encryption leaf */
> + movl $0x80000000, %eax
> + cpuid
> + cmpl $0x8000001f, %eax
> + jb .Lno_mem_encrypt
> +
> + /*
> + * Check for memory encryption feature:
> + * CPUID Fn8000_001F[EAX] - Bit 0
> + */
> + movl $0x8000001f, %eax
> + cpuid
> + bt $0, %eax
> + jnc .Lno_mem_encrypt
> +
> + /* Check for the mem_encrypt=on command line option */
> + push %rsi /* Save RSI (real_mode_data) */
> + movl BP_ext_cmd_line_ptr(%rsi), %ecx
> + shlq $32, %rcx
> + movl BP_cmd_line_ptr(%rsi), %edi
> + addq %rcx, %rdi
> + leaq mem_encrypt_enable_option(%rip), %rsi
> + call cmdline_find_option_bool
> + pop %rsi /* Restore RSI (real_mode_data) */
> + testl %eax, %eax
> + jz .Lno_mem_encrypt
Can you move parts to C here, so that it is more readable?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures)
http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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