[PATCH v3 07/13] arm64: cpufeature: Detect HCR_EL2.NV1 being RES0

[Marc Zyngier]

A variant of FEAT_E2H0 not being implemented exists in the form of
HCR_EL2.E2H being RES1 *and* HCR_EL2.NV1 being RES0 (indicating that
only VHE is supported on the host and nested guests).

Add the necessary infrastructure for this new CPU capability.

Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kernel/cpufeature.c | 7 +++++++
 arch/arm64/tools/cpucaps       | 1 +
 2 files changed, 8 insertions(+)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6ef9811f7bb7..64a026cc5cec 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2793,6 +2793,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.matches = has_cpuid_feature,
 		ARM64_CPUID_FIELDS_NEG(ID_AA64MMFR4_EL1, E2H0, NI)
 	},
+	{
+		.desc = "FEAT_E2H0 not implemented (NV1 RES0)",
+		.capability = ARM64_HCR_NV1_RES0,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
+		.matches = has_cpuid_feature,
+		ARM64_CPUID_FIELDS_NEG(ID_AA64MMFR4_EL1, E2H0, NI_NV1)
+	},
 	{},
 };
 
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 8866ea9bf995..fea24bcd6252 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -53,6 +53,7 @@ HAS_TLB_RANGE
 HAS_VIRT_HOST_EXTN
 HAS_WFXT
 HCR_E2H_RES1
+HCR_NV1_RES0
 HW_DBM
 KVM_HVHE
 KVM_PROTECTED_MODE
-- 
2.39.2