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

From: Tom Lendacky
Date: Thu Aug 10 2017 - 09:03:38 EST


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@xxxxxxx>

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@xxxxxxx>
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
---
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