[PATCH v3 1/5] x86/boot/compressed/64: Introduce sev_status

From: Joerg Roedel
Date: Wed Oct 21 2020 - 08:40:10 EST


From: Joerg Roedel <jroedel@xxxxxxx>

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>
---
arch/x86/boot/compressed/mem_encrypt.S | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S
index dd07e7b41b11..2192b3bd78d8 100644
--- a/arch/x86/boot/compressed/mem_encrypt.S
+++ b/arch/x86/boot/compressed/mem_encrypt.S
@@ -81,6 +81,13 @@ SYM_FUNC_START(set_sev_encryption_mask)

bts %rax, sme_me_mask(%rip) /* Create the encryption mask */

+ /* Read sev_status */
+ movl $MSR_AMD64_SEV, %ecx
+ rdmsr
+ shlq $32, %rdx
+ orq %rdx, %rax
+ movq %rax, sev_status(%rip)
+
.Lno_sev_mask:
movq %rbp, %rsp /* Restore original stack pointer */

@@ -96,5 +103,6 @@ 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
--
2.28.0