[PATCH v6 59/64] KVM: arm64: Add ARMv8.4 Enhanced Nested Virt cpufeature

Marc Zyngier
2022-01-28T12:51:15Z

Add the detection code for the ARMv8.4-NV feature.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/kvm_nested.h | 6 ++++++
arch/arm64/kernel/cpufeature.c | 10 ++++++++++
arch/arm64/tools/cpucaps | 1 +
3 files changed, 17 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 3b5838a2f29e..57b14474a062 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 2fa39ce108d0..6e0577d3bf63 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2029,6 +2029,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.field_pos = ID_AA64MMFR2_NV_SHIFT,
.min_field_value = 1,
},
+ {
+ .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_NV_SHIFT,
+ .min_field_value = 2,
+ },
{
.capability = ARM64_HAS_32BIT_EL0_DO_NOT_USE,
.type = ARM64_CPUCAP_SYSTEM_FEATURE,
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index a49864b56a07..3f6f567d2811 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -19,6 +19,7 @@ HAS_DCPODP
HAS_DCPOP
HAS_E0PD
HAS_ECV
+HAS_ENHANCED_NESTED_VIRT
HAS_EPAN
HAS_GENERIC_AUTH
HAS_GENERIC_AUTH_ARCH