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

Joerg Roedel
2020-09-07T13:15:38Z

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 at suse.de>
Reviewed-by: Kees Cook <keescook at chromium.org>
---
 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