From da9af5071b25cb81682c3506c96516fe55186577 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 22 Jan 2024 18:13:40 +0000 Subject: [PATCH] arm64: cpufeature: Detect HCR_EL2.NV1 being RES0 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 Signed-off-by: Marc Zyngier Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20240122181344.258974-7-maz@kernel.org Signed-off-by: Oliver Upton --- arch/arm64/kernel/cpufeature.c | 12 ++++++++++++ arch/arm64/tools/cpucaps | 1 + 2 files changed, 13 insertions(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index ad3753fbdcb1..91249d20883b 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1794,6 +1794,11 @@ static bool unmap_kernel_at_el0(const struct arm64_cpu_capabilities *entry, return !meltdown_safe; } +static bool has_nv1(const struct arm64_cpu_capabilities *entry, int scope) +{ + return !has_cpuid_feature(entry, scope); +} + #if defined(ID_AA64MMFR0_EL1_TGRAN_LPA2) && defined(ID_AA64MMFR0_EL1_TGRAN_2_SUPPORTED_LPA2) static bool has_lpa2_at_stage1(u64 mmfr0) { @@ -2794,6 +2799,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = has_lpa2, }, + { + .desc = "NV1", + .capability = ARM64_HAS_HCR_NV1, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_nv1, + ARM64_CPUID_FIELDS_NEG(ID_AA64MMFR4_EL1, E2H0, NI_NV1) + }, {}, }; diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index b912b1409fc0..65090dd34641 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -35,6 +35,7 @@ HAS_GENERIC_AUTH_IMP_DEF HAS_GIC_CPUIF_SYSREGS HAS_GIC_PRIO_MASKING HAS_GIC_PRIO_RELAXED_SYNC +HAS_HCR_NV1 HAS_HCX HAS_LDAPR HAS_LPA2 -- 2.39.5