This is a note to let you know that I've just added the patch titled
x86/boot/compressed/64: Introduce sev_status
to the 5.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-boot-compressed-64-introduce-sev_status.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d1fef12fa6284c24ba55e73fa9019adfcad190a8
Author: Joerg Roedel <jroedel@xxxxxxx>
Date: Wed Oct 28 17:46:55 2020 +0100
x86/boot/compressed/64: Introduce sev_status
[ Upstream commit 3ad84246a4097010f3ae3d6944120c0be00e9e7a ]
Introduce sev_status and initialize it together with sme_me_mask to have
an indicator which SEV features are enabled.
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Link: https://lkml.kernel.org/r/20201028164659.27002-2-joro@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S
index dd07e7b41b115..3092ae173f94e 100644
--- a/arch/x86/boot/compressed/mem_encrypt.S
+++ b/arch/x86/boot/compressed/mem_encrypt.S
@@ -81,6 +81,19 @@ SYM_FUNC_START(set_sev_encryption_mask)
bts %rax, sme_me_mask(%rip) /* Create the encryption mask */
+ /*
+ * Read MSR_AMD64_SEV again and store it to sev_status. Can't do this in
+ * get_sev_encryption_bit() because this function is 32-bit code and
+ * shared between 64-bit and 32-bit boot path.
+ */
+ movl $MSR_AMD64_SEV, %ecx /* Read the SEV MSR */
+ rdmsr
+
+ /* Store MSR value in sev_status */
+ shlq $32, %rdx
+ orq %rdx, %rax
+ movq %rax, sev_status(%rip)
+
.Lno_sev_mask:
movq %rbp, %rsp /* Restore original stack pointer */
@@ -96,5 +109,6 @@ SYM_FUNC_END(set_sev_encryption_mask)
#ifdef CONFIG_AMD_MEM_ENCRYPT
.balign 8
-SYM_DATA(sme_me_mask, .quad 0)
+SYM_DATA(sme_me_mask, .quad 0)
+SYM_DATA(sev_status, .quad 0)
#endif
