[v10] AMD: Add Secure AVIC Guest Support

[PATCH v10 18/18] x86/sev: Indicate SEV-SNP guest supports Secure AVIC

Posted by Neeraj Upadhyay 1 month ago

Now that Secure AVIC support is added in the guest, indicate SEV-SNP
guest supports Secure AVIC feature if AMD_SECURE_AVIC config is
enabled.

Co-developed-by: Kishon Vijay Abraham I <kvijayab@amd.com>
Signed-off-by: Kishon Vijay Abraham I <kvijayab@amd.com>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
---
Changes since v9:
 - No change.

 arch/x86/boot/compressed/sev.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 74e083feb2d9..048d3e8839c3 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -238,13 +238,20 @@ bool sev_es_check_ghcb_fault(unsigned long address)
 				 MSR_AMD64_SNP_SECURE_AVIC |		\
 				 MSR_AMD64_SNP_RESERVED_MASK)
 
+#ifdef CONFIG_AMD_SECURE_AVIC
+#define SNP_FEATURE_SECURE_AVIC		MSR_AMD64_SNP_SECURE_AVIC
+#else
+#define SNP_FEATURE_SECURE_AVIC		0
+#endif
+
 /*
  * SNP_FEATURES_PRESENT is the mask of SNP features that are implemented
  * by the guest kernel. As and when a new feature is implemented in the
  * guest kernel, a corresponding bit should be added to the mask.
  */
 #define SNP_FEATURES_PRESENT	(MSR_AMD64_SNP_DEBUG_SWAP |	\
-				 MSR_AMD64_SNP_SECURE_TSC)
+				 MSR_AMD64_SNP_SECURE_TSC |	\
+				 SNP_FEATURE_SECURE_AVIC)
 
 u64 snp_get_unsupported_features(u64 status)
 {
-- 
2.34.1

[tip: x86/apic] x86/sev: Indicate the SEV-SNP guest supports Secure AVIC

Posted by tip-bot2 for Neeraj Upadhyay 1 month ago

The following commit has been merged into the x86/apic branch of tip:

Commit-ID:     27a17e02418e978198513edfb389b65237f4eaf5
Gitweb:        https://git.kernel.org/tip/27a17e02418e978198513edfb389b65237f4eaf5
Author:        Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
AuthorDate:    Thu, 28 Aug 2025 17:02:24 +05:30
Committer:     Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Mon, 01 Sep 2025 13:20:53 +02:00

x86/sev: Indicate the SEV-SNP guest supports Secure AVIC

Now that Secure AVIC support is complete, make it part of to the SNP present
features.

Co-developed-by: Kishon Vijay Abraham I <kvijayab@amd.com>
Signed-off-by: Kishon Vijay Abraham I <kvijayab@amd.com>
Signed-off-by: Neeraj Upadhyay <Neeraj.Upadhyay@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Tianyu Lan <tiala@microsoft.com>
Link: https://lore.kernel.org/20250828113225.209174-1-Neeraj.Upadhyay@amd.com
---
 arch/x86/boot/compressed/sev.c |  9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c
index 74e083f..048d3e8 100644
--- a/arch/x86/boot/compressed/sev.c
+++ b/arch/x86/boot/compressed/sev.c
@@ -238,13 +238,20 @@ bool sev_es_check_ghcb_fault(unsigned long address)
 				 MSR_AMD64_SNP_SECURE_AVIC |		\
 				 MSR_AMD64_SNP_RESERVED_MASK)
 
+#ifdef CONFIG_AMD_SECURE_AVIC
+#define SNP_FEATURE_SECURE_AVIC		MSR_AMD64_SNP_SECURE_AVIC
+#else
+#define SNP_FEATURE_SECURE_AVIC		0
+#endif
+
 /*
  * SNP_FEATURES_PRESENT is the mask of SNP features that are implemented
  * by the guest kernel. As and when a new feature is implemented in the
  * guest kernel, a corresponding bit should be added to the mask.
  */
 #define SNP_FEATURES_PRESENT	(MSR_AMD64_SNP_DEBUG_SWAP |	\
-				 MSR_AMD64_SNP_SECURE_TSC)
+				 MSR_AMD64_SNP_SECURE_TSC |	\
+				 SNP_FEATURE_SECURE_AVIC)
 
 u64 snp_get_unsupported_features(u64 status)
 {