From e2d6c906f0ac69559da887c0a2c3c10070e746c5 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 9 Jun 2023 17:21:47 +0100 Subject: [PATCH] arm64: Add KVM_HVHE capability and has_hvhe() predicate Expose a capability keying the hVHE feature as well as a new predicate testing it. Nothing is so far using it, and nothing is enabling it yet. Signed-off-by: Marc Zyngier Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20230609162200.2024064-5-maz@kernel.org Signed-off-by: Oliver Upton --- arch/arm64/include/asm/cpufeature.h | 1 + arch/arm64/include/asm/virt.h | 8 ++++++++ arch/arm64/kernel/cpufeature.c | 19 +++++++++++++++++++ arch/arm64/tools/cpucaps | 1 + 4 files changed, 29 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index bc10098..3d4b547 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -16,6 +16,7 @@ #define cpu_feature(x) KERNEL_HWCAP_ ## x #define ARM64_SW_FEATURE_OVERRIDE_NOKASLR 0 +#define ARM64_SW_FEATURE_OVERRIDE_HVHE 4 #ifndef __ASSEMBLY__ diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 21e9406..5227db7 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -142,6 +142,14 @@ static __always_inline bool is_protected_kvm_enabled(void) return cpus_have_final_cap(ARM64_KVM_PROTECTED_MODE); } +static __always_inline bool has_hvhe(void) +{ + if (is_vhe_hyp_code()) + return false; + + return cpus_have_final_cap(ARM64_KVM_HVHE); +} + static inline bool is_hyp_nvhe(void) { return is_hyp_mode_available() && !is_kernel_in_hyp_mode(); diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 2d2b7bb..c743b1a 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1998,6 +1998,19 @@ static bool has_nested_virt_support(const struct arm64_cpu_capabilities *cap, return true; } +static bool hvhe_possible(const struct arm64_cpu_capabilities *entry, + int __unused) +{ + u64 val; + + val = read_sysreg(id_aa64mmfr1_el1); + if (!cpuid_feature_extract_unsigned_field(val, ID_AA64MMFR1_EL1_VH_SHIFT)) + return false; + + val = arm64_sw_feature_override.val & arm64_sw_feature_override.mask; + return cpuid_feature_extract_unsigned_field(val, ARM64_SW_FEATURE_OVERRIDE_HVHE); +} + #ifdef CONFIG_ARM64_PAN static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused) { @@ -2643,6 +2656,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .cpu_enable = cpu_enable_dit, ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, DIT, IMP) }, + { + .desc = "VHE for hypervisor only", + .capability = ARM64_KVM_HVHE, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = hvhe_possible, + }, {}, }; diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 40ba954..3c23a55 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -47,6 +47,7 @@ HAS_TLB_RANGE HAS_VIRT_HOST_EXTN HAS_WFXT HW_DBM +KVM_HVHE KVM_PROTECTED_MODE MISMATCHED_CACHE_TYPE MTE -- 2.7.4