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arm64: cpufeature: detect FEAT_HCX

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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@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
Link: https://lore.kernel.org/r/20230509142235.3284028-3-kristina.martsenko@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Kristina Martsenko 2023-05-09 15:22:26 +01:00 committed by Catalin Marinas
parent af94aad4c9
commit b0c756fe99
2 changed files with 9 additions and 0 deletions
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8
arch/arm64/kernel/cpufeature.c
View File

@ -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)",

1
arch/arm64/tools/cpucaps
View File

@ -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