Re: [RFC Part1 PATCH v3 05/17] x86, realmode: Don't decrypt trampoline area under SEV

Tom Lendacky
2017-08-10T13:03:12Z

On 7/26/2017 11:03 AM, Borislav Petkov wrote:
> Subject: x86/realmode: ...

Done.

>
> On Mon, Jul 24, 2017 at 02:07:45PM -0500, Brijesh Singh wrote:
>> From: Tom Lendacky <thomas.lendacky@amd.com>
>>
>> When SEV is active the trampoline area will need to be in encrypted
>> memory so only mark the area decrypted if SME is active.
>>
>> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
>> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
>> ---
>> arch/x86/realmode/init.c | 6 ++++--
>> 1 file changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
>> index 1f71980..c7eeca7 100644
>> --- a/arch/x86/realmode/init.c
>> +++ b/arch/x86/realmode/init.c
>> @@ -63,9 +63,11 @@ static void __init setup_real_mode(void)
>> /*
>> * If SME is active, the trampoline area will need to be in
>> * decrypted memory in order to bring up other processors
>> - * successfully.
>> + * successfully. For SEV the trampoline area needs to be in
>> + * encrypted memory, so only do this for SME.
>
> Or simply say:
>
> "It is not needed for SEV."

Will do.

Thanks,
Tom

>