[Part1,v7,04/17] x86/realmode: Don't decrypt trampoline area under SEV

Commit Message

Brijesh Singh Oct. 20, 2017, 2:30 p.m. UTC

From: Tom Lendacky <[e-mail]>

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 <[e-mail]>
Signed-off-by: Brijesh Singh <[e-mail]>
Reviewed-by: Borislav Petkov <[e-mail]>
Tested-by: Borislav Petkov <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: "H. Peter Anvin" <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Andy Lutomirski <[e-mail]>
Cc: Laura Abbott <[e-mail]>
Cc: "Kirill A. Shutemov" <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
---
 arch/x86/realmode/init.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 1f71980fc5e0..d03125c2b73b 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -63,9 +63,10 @@  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. This is not needed for SEV.
 	 */
-	set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT);
+	if (sme_active())
+		set_memory_decrypted((unsigned long)base, size >> PAGE_SHIFT);
 
 	memcpy(base, real_mode_blob, size);