[Part1 PATCH v7 03/17] x86/mm: Don't attempt to encrypt initrd under SEV

From: Brijesh Singh
Date: Fri Oct 20 2017 - 10:31:32 EST


From: Tom Lendacky <thomas.lendacky@xxxxxxx>

When SEV is active the initrd/initramfs will already have already been
placed in memory encrypted so do not try to encrypt it.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Tested-by: Borislav Petkov <bp@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: x86@xxxxxxxxxx
---
arch/x86/kernel/setup.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 17dea09f06a3..bb5c3b4ea00f 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -368,9 +368,11 @@ static void __init reserve_initrd(void)
* If SME is active, this memory will be marked encrypted by the
* kernel when it is accessed (including relocation). However, the
* ramdisk image was loaded decrypted by the bootloader, so make
- * sure that it is encrypted before accessing it.
+ * sure that it is encrypted before accessing it. For SEV the
+ * ramdisk will already be encrypted, so only do this for SME.
*/
- sme_early_encrypt(ramdisk_image, ramdisk_end - ramdisk_image);
+ if (sme_active())
+ sme_early_encrypt(ramdisk_image, ramdisk_end - ramdisk_image);

initrd_start = 0;

--
2.9.5