On 10/28/20 11:46 AM, Joerg Roedel wrote:
> From: Joerg Roedel <[email protected]>
>
> Introduce sev_status and initialize it together with sme_me_mask to have
> an indicator which SEV features are enabled.
>
> Signed-off-by: Joerg Roedel <[email protected]>
Reviewed-by: Tom Lendacky <[email protected]>
> ---
> arch/x86/boot/compressed/mem_encrypt.S | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S
> index dd07e7b41b11..0bae1ca658d9 100644
> --- a/arch/x86/boot/compressed/mem_encrypt.S
> +++ b/arch/x86/boot/compressed/mem_encrypt.S
> @@ -81,6 +81,19 @@ SYM_FUNC_START(set_sev_encryption_mask)
>
> bts %rax, sme_me_mask(%rip) /* Create the encryption mask */
>
> + /*
> + * Read MSR_AMD64_SEV again and store it to sev_status. Can't do this in
> + * get_sev_encryption_bit() because this function is 32 bit code and
> + * shared between 64 bit and 32 bit boot path.
> + */
> + movl $MSR_AMD64_SEV, %ecx /* Read the SEV MSR */
> + rdmsr
> +
> + /* Store MSR value in sev_status */
> + shlq $32, %rdx
> + orq %rdx, %rax
> + movq %rax, sev_status(%rip)
> +
> .Lno_sev_mask:
> movq %rbp, %rsp /* Restore original stack pointer */
>
> @@ -96,5 +109,6 @@ SYM_FUNC_END(set_sev_encryption_mask)
>
> #ifdef CONFIG_AMD_MEM_ENCRYPT
> .balign 8
> -SYM_DATA(sme_me_mask, .quad 0)
> +SYM_DATA(sme_me_mask, .quad 0)
> +SYM_DATA(sev_status, .quad 0)
> #endif
>