[PATCH v7 37/72] x86/sev-es: Print SEV-ES info into kernel log

From: Joerg Roedel
Date: Mon Sep 07 2020 - 09:28:45 EST


From: Joerg Roedel <jroedel@xxxxxxx>

Refactor the message printed to the kernel log which indicates whether
SEV or SME is active to print a list of enabled encryption features.
This will scale better in the future when more memory encryption
features might be added. Also add SEV-ES to the list of features.

Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
arch/x86/mm/mem_encrypt.c | 29 ++++++++++++++++++++++++++---
1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index d0d4ebcec1be..d6b8f4c1d3fa 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -407,6 +407,31 @@ void __init mem_encrypt_free_decrypted_mem(void)
free_init_pages("unused decrypted", vaddr, vaddr_end);
}

+static void print_mem_encrypt_feature_info(void)
+{
+ pr_info("AMD Memory Encryption Features active:");
+
+ /* Secure Memory Encryption */
+ if (sme_active()) {
+ /*
+ * SME is mutually exclusive with any of the SEV
+ * features below.
+ */
+ pr_cont(" SME\n");
+ return;
+ }
+
+ /* Secure Encrypted Virtualization */
+ if (sev_active())
+ pr_cont(" SEV");
+
+ /* Encrypted Register State */
+ if (sev_es_active())
+ pr_cont(" SEV-ES");
+
+ pr_cont("\n");
+}
+
/* Architecture __weak replacement functions */
void __init mem_encrypt_init(void)
{
@@ -422,8 +447,6 @@ void __init mem_encrypt_init(void)
if (sev_active())
static_branch_enable(&sev_enable_key);

- pr_info("AMD %s active\n",
- sev_active() ? "Secure Encrypted Virtualization (SEV)"
- : "Secure Memory Encryption (SME)");
+ print_mem_encrypt_feature_info();
}

--
2.28.0