[PATCH v9 41/50] KVM: arm64: Add FEAT_NV2 cpu feature

[Marc Zyngier]

Add the detection code for the FEAT_NV2 feature.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/include/asm/kvm_nested.h |  6 ++++++
 arch/arm64/kernel/cpufeature.c      | 11 +++++++++++
 2 files changed, 17 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 784168dcb0fe..a58c3df12379 100644
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -14,6 +14,12 @@ static inline bool vcpu_has_nv(const struct kvm_vcpu *vcpu)
 		test_bit(KVM_ARM_VCPU_HAS_EL2, vcpu->arch.features));
 }
 
+static inline bool vcpu_has_nv2(const struct kvm_vcpu *vcpu)
+{
+	return cpus_have_final_cap(ARM64_HAS_ENHANCED_NESTED_VIRT) &&
+		vcpu_has_nv(vcpu);
+}
+
 /* Translation helpers from non-VHE EL2 to EL1 */
 static inline u64 tcr_el2_ps_to_tcr_el1_ips(u64 tcr_el2)
 {
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index c331c49a7d19..db877f1d3a7b 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2298,6 +2298,17 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.field_width = 4,
 		.min_field_value = ID_AA64MMFR2_EL1_NV_IMP,
 	},
+	{
+		.desc = "Enhanced Nested Virtualization Support",
+		.capability = ARM64_HAS_ENHANCED_NESTED_VIRT,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = has_nested_virt_support,
+		.sys_reg = SYS_ID_AA64MMFR2_EL1,
+		.sign = FTR_UNSIGNED,
+		.field_pos = ID_AA64MMFR2_EL1_NV_SHIFT,
+		.field_width = 4,
+		.min_field_value = ID_AA64MMFR2_EL1_NV_NV2,
+	},
 	{
 		.capability = ARM64_HAS_32BIT_EL0_DO_NOT_USE,
 		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
-- 
2.34.1