From: Kristina Martsenko <kristina.martsenko@xxxxxxx> [ Upstream commit b0c756fe996ac930033882ca56410639e5cad1ec ] Detect if the system has the new HCRX_EL2 register added in ARMv8.7/9.2, so that subsequent patches can check for its presence. KVM currently relies on the register being present on all CPUs (or none), so the kernel will panic if that is not the case. Fortunately no such systems currently exist, but this can be revisited if they appear. Note that the kernel will not panic if CONFIG_KVM is disabled. Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Kristina Martsenko <kristina.martsenko@xxxxxxx> Link: https://lore.kernel.org/r/20230509142235.3284028-3-kristina.martsenko@xxxxxxx Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- arch/arm64/kernel/cpufeature.c | 8 ++++++++ arch/arm64/tools/cpucaps | 1 + 2 files changed, 9 insertions(+) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 7d7128c651614..9898ad77b1dba 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -364,6 +364,7 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = { static const struct arm64_ftr_bits ftr_id_aa64mmfr1[] = { ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_TIDCP1_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_AFP_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_HCX_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_ETS_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_TWED_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR1_EL1_XNX_SHIFT, 4, 0), @@ -2309,6 +2310,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .type = ARM64_CPUCAP_SYSTEM_FEATURE, .matches = is_kvm_protected_mode, }, + { + .desc = "HCRX_EL2 register", + .capability = ARM64_HAS_HCX, + .type = ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS(ID_AA64MMFR1_EL1, HCX, IMP) + }, #endif { .desc = "Kernel page table isolation (KPTI)", diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index 40ba95472594d..e1de10fa080e0 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -32,6 +32,7 @@ HAS_GENERIC_AUTH_IMP_DEF HAS_GIC_CPUIF_SYSREGS HAS_GIC_PRIO_MASKING HAS_GIC_PRIO_RELAXED_SYNC +HAS_HCX HAS_LDAPR HAS_LSE_ATOMICS HAS_NESTED_VIRT -- 2.39.2
