[PATCH v2 19/20] KVM: s390: arm64: Promote PTRAUTH capability

[Steffen Eiden]

Promote the pointer authentication capability if supported by hardware.

Signed-off-by: Steffen Eiden <seiden@xxxxxxxxxxxxx>
---
 arch/s390/include/asm/kvm_host_arm64.h |  8 ++------
 arch/s390/kvm/arm64/arm.c              |  9 +++++++++
 arch/s390/kvm/arm64/feature.c          | 18 ++++++++++++++++++
 arch/s390/kvm/arm64/feature.h          |  5 +++++
 4 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/arch/s390/include/asm/kvm_host_arm64.h b/arch/s390/include/asm/kvm_host_arm64.h
index 73eb09e98848..32facf045704 100644
--- a/arch/s390/include/asm/kvm_host_arm64.h
+++ b/arch/s390/include/asm/kvm_host_arm64.h
@@ -32,6 +32,8 @@ bool cpus_have_final_cap(unsigned int num);
 #define KVM_HAVE_MMU_RWLOCK
 #define KVM_MAX_VCPUS 1
 #define KVM_S390_ARM64_IMPL_FEATURES (		\
+	 BIT(KVM_ARM_VCPU_PTRAUTH_ADDRESS) |	\
+	 BIT(KVM_ARM_VCPU_PTRAUTH_GENERIC) |	\
 	 BIT(KVM_ARM_VCPU_SVE)			\
 )
 
@@ -133,7 +135,6 @@ struct kvm_vcpu_stat {
 };
 
 #define kvm_has_mte(_kvm) false
-#define vcpu_has_ptrauth(_vcpu) false
 
 struct kvm_arch_memory_slot {
 };
@@ -170,11 +171,6 @@ struct kvm_vm_stat {
 	struct kvm_vm_stat_generic generic;
 };
 
-static inline bool system_has_full_ptr_auth(void)
-{
-	return true;
-}
-
 #define kvm_vm_is_protected(_kvm) false
 #define vcpu_is_protected(_vcpu) false
 
diff --git a/arch/s390/kvm/arm64/arm.c b/arch/s390/kvm/arm64/arm.c
index a46c9c62a5f9..ebd8045c0900 100644
--- a/arch/s390/kvm/arm64/arm.c
+++ b/arch/s390/kvm/arm64/arm.c
@@ -57,6 +57,10 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_ARM_SVE:
 		ret = system_supports_sve();
 		break;
+	case KVM_CAP_ARM_PTRAUTH_ADDRESS:
+	case KVM_CAP_ARM_PTRAUTH_GENERIC:
+		ret = kvm_has_full_ptr_auth();
+		break;
 	default:
 		ret = 0;
 	}
@@ -265,6 +269,11 @@ static unsigned long system_supported_vcpu_features(void)
 	if (!system_supports_sve())
 		clear_bit(KVM_ARM_VCPU_SVE, &features);
 
+	if (!kvm_has_full_ptr_auth()) {
+		clear_bit(KVM_ARM_VCPU_PTRAUTH_ADDRESS, &features);
+		clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features);
+	}
+
 	return features;
 }
 
diff --git a/arch/s390/kvm/arm64/feature.c b/arch/s390/kvm/arm64/feature.c
index 3847cdd2f92b..a2848e4b3e62 100644
--- a/arch/s390/kvm/arm64/feature.c
+++ b/arch/s390/kvm/arm64/feature.c
@@ -170,3 +170,21 @@ bool system_supports_sve(void)
 			     read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1)) ==
 		       ID_AA64PFR0_EL1_SVE_IMP;
 }
+
+bool system_has_full_ptr_auth(void)
+{
+	u64 isar1 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR1_EL1);
+	u64 isar2 = read_sanitised_ftr_reg(SYS_ID_AA64ISAR2_EL1);
+	bool address_auth;
+	bool generic_auth;
+
+	address_auth = SYS_FIELD_GET(ID_AA64ISAR1_EL1, APA, isar1) >= ID_AA64ISAR1_EL1_APA_PAuth ||
+		       SYS_FIELD_GET(ID_AA64ISAR1_EL1, API, isar1) >= ID_AA64ISAR1_EL1_API_PAuth ||
+		       SYS_FIELD_GET(ID_AA64ISAR2_EL1, APA3, isar2) >= ID_AA64ISAR2_EL1_APA3_PAuth;
+
+	generic_auth = SYS_FIELD_GET(ID_AA64ISAR1_EL1, GPA, isar1) >= ID_AA64ISAR1_EL1_GPA_IMP ||
+		       SYS_FIELD_GET(ID_AA64ISAR1_EL1, GPI, isar1) >= ID_AA64ISAR1_EL1_GPI_IMP ||
+		       SYS_FIELD_GET(ID_AA64ISAR2_EL1, GPA3, isar2) >= ID_AA64ISAR2_EL1_GPA3_IMP;
+
+	return address_auth && generic_auth;
+}
diff --git a/arch/s390/kvm/arm64/feature.h b/arch/s390/kvm/arm64/feature.h
index 892cf8bcf3a1..c11ac0daa428 100644
--- a/arch/s390/kvm/arm64/feature.h
+++ b/arch/s390/kvm/arm64/feature.h
@@ -94,4 +94,9 @@ static inline u64 kvm_sae_irptc(void)
 
 bool system_supports_sve(void);
 
+#define vcpu_has_ptrauth(vcpu)						\
+	 (vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_ADDRESS) ||       \
+	  vcpu_has_feature(vcpu, KVM_ARM_VCPU_PTRAUTH_GENERIC))
+bool system_has_full_ptr_auth(void);
+
 #endif /* ARCH_S390_KVM_FEATURE_H */
-- 
2.53.0