[tip:x86/asm] x86/mm: Don't attempt to encrypt initrd under SEV

tip-bot for Tom Lendacky
2017-11-07T14:45:59Z

Commit-ID: 682af54399b6111730aec0be63e5f6a3a3359a76
Gitweb: https://git.kernel.org/tip/682af54399b6111730aec0be63e5f6a3a3359a76
Author: Tom Lendacky <thomas.lendacky@amd.com>
AuthorDate: Fri, 20 Oct 2017 09:30:45 -0500
Committer: Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 7 Nov 2017 15:35:55 +0100

x86/mm: Don't attempt to encrypt initrd under SEV

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@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20171020143059.3291-4-brijesh.singh@amd.com

---
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 0957dd7..507100a 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -380,9 +380,11 @@ 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;