| Message ID | 20231120123721.851738-7-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Add support for FEAT_E2H0, or lack thereof | expand |
On 20/11/2023 12:37, Marc Zyngier wrote: > FEAT_E2H0 is a new feature that indicates whether or not HCR_EL2.E2H > can be set to 0. Amusingly, this feature is set to 0 when implemented, > and otherwise negative. > > Add a new capability and detection infrastructure to detect the > absence of FEAT_E2H0. > > Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > arch/arm64/kernel/cpufeature.c | 7 +++++++ > arch/arm64/tools/cpucaps | 1 + > 2 files changed, 8 insertions(+) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 41db7f993eef..e0d64e8b4851 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -2787,6 +2787,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { > .matches = has_cpuid_feature, > ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, EVT, IMP) > }, > + { > + .desc = "FEAT_E2H0 not implemented", > + .capability = ARM64_HCR_E2H_RES1, > + .type = ARM64_CPUCAP_SYSTEM_FEATURE, > + .matches = has_cpuid_feature, > + ARM64_CPUID_FIELDS_NEG(ID_AA64MMFR4_EL1, E2H0, NI) > + }, > {}, > }; > > diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps > index b98c38288a9d..8866ea9bf995 100644 > --- a/arch/arm64/tools/cpucaps > +++ b/arch/arm64/tools/cpucaps > @@ -52,6 +52,7 @@ HAS_TIDCP1 > HAS_TLB_RANGE > HAS_VIRT_HOST_EXTN > HAS_WFXT > +HCR_E2H_RES1 > HW_DBM > KVM_HVHE > KVM_PROTECTED_MODE
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 41db7f993eef..e0d64e8b4851 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -2787,6 +2787,13 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .matches = has_cpuid_feature, ARM64_CPUID_FIELDS(ID_AA64MMFR2_EL1, EVT, IMP) }, + { + .desc = "FEAT_E2H0 not implemented", + .capability = ARM64_HCR_E2H_RES1, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + ARM64_CPUID_FIELDS_NEG(ID_AA64MMFR4_EL1, E2H0, NI) + }, {}, }; diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps index b98c38288a9d..8866ea9bf995 100644 --- a/arch/arm64/tools/cpucaps +++ b/arch/arm64/tools/cpucaps @@ -52,6 +52,7 @@ HAS_TIDCP1 HAS_TLB_RANGE HAS_VIRT_HOST_EXTN HAS_WFXT +HCR_E2H_RES1 HW_DBM KVM_HVHE KVM_PROTECTED_MODE
FEAT_E2H0 is a new feature that indicates whether or not HCR_EL2.E2H can be set to 0. Amusingly, this feature is set to 0 when implemented, and otherwise negative. Add a new capability and detection infrastructure to detect the absence of FEAT_E2H0. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kernel/cpufeature.c | 7 +++++++ arch/arm64/tools/cpucaps | 1 + 2 files changed, 8 insertions(+)