[PATCH v7 6/7] KVM: arm64: Enable FEAT_{LS64, LS64_V} in the supported guest

[Zhou Wang]

On 2025/11/8 2:53, Oliver Upton wrote:
> Hi Zhou,
> 
> On Fri, Nov 07, 2025 at 03:21:26PM +0800, Zhou Wang wrote:
>> From: Yicong Yang <yangyicong at hisilicon.com>
>>
>> Using FEAT_{LS64, LS64_V} instructions in a guest is also controlled
>> by HCRX_EL2.{EnALS, EnASR}. Enable it if guest has related feature.
>>
>> Signed-off-by: Yicong Yang <yangyicong at hisilicon.com>
>> Signed-off-by: Zhou Wang <wangzhou1 at hisilicon.com>
> 
> The ordering of this patch is incorrect as patch #5 has the side-effect
> of exposing ID_AA64ISAR1_EL1.LS64 to KVM guests. This one should come
> first instead.
Hi Oliver,

I got this point, will change the order in next version.

Thanks,
Zhou

> 
> Thanks,
> Oliver
> 
>> ---
>>  arch/arm64/include/asm/kvm_emulate.h | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
>> index bab967d65715..29291e25ecfd 100644
>> --- a/arch/arm64/include/asm/kvm_emulate.h
>> +++ b/arch/arm64/include/asm/kvm_emulate.h
>> @@ -695,6 +695,12 @@ static inline void vcpu_set_hcrx(struct kvm_vcpu *vcpu)
>>  
>>  		if (kvm_has_sctlr2(kvm))
>>  			vcpu->arch.hcrx_el2 |= HCRX_EL2_SCTLR2En;
>> +
>> +		if (kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64))
>> +			vcpu->arch.hcrx_el2 |= HCRX_EL2_EnALS;
>> +
>> +		if (kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_V))
>> +			vcpu->arch.hcrx_el2 |= HCRX_EL2_EnASR;
>>  	}
>>  }
>>  #endif /* __ARM64_KVM_EMULATE_H__ */
>> -- 
>> 2.33.0
>>
>>
> 
> .