diff options
| author | Marc Zyngier <maz@kernel.org> | 2023-06-09 17:21:47 +0100 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2023-06-12 23:17:23 +0000 |
| commit | e2d6c906f0ac69559da887c0a2c3c10070e746c5 (patch) | |
| tree | fae40aa09fde93a947cb9927958e38d47d722a8a | |
| parent | 0ddc312b7c73049d982d173fee4c5dabf1727ebb (diff) | |
| download | lwn-e2d6c906f0ac69559da887c0a2c3c10070e746c5.tar.gz lwn-e2d6c906f0ac69559da887c0a2c3c10070e746c5.zip | |
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 <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20230609162200.2024064-5-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/virt.h | 8 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 19 | ||||
| -rw-r--r-- | arch/arm64/tools/cpucaps | 1 |
4 files changed, 29 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index bc1009890180..3d4b547ae312 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 21e94068804d..5227db7640c8 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 2d2b7bb5fa0c..c743b1a5ae31 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 40ba95472594..3c23a55d7c2f 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 |