Reply-To: Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH v4 01/21] KVM: arm64: Introduce template for inline
 functions
To:     Eric Auger <eauger@redhat.com>, kvmarm@lists.cs.columbia.edu
Cc:     maz@kernel.org, linux-kernel@vger.kernel.org,
        Jonathan.Cameron@huawei.com, pbonzini@redhat.com, will@kernel.org
References: <20210815001352.81927-1-gshan@redhat.com>
 <20210815001352.81927-2-gshan@redhat.com>
 <5112b3ba-d038-f622-c67f-e53695cbef37@redhat.com>
From:   Gavin Shan <gshan@redhat.com>
Message-ID: <8b7d3a75-dbf8-c8b9-bbb6-bd89d9429802@redhat.com>
Date:   Tue, 11 Jan 2022 15:52:44 +0800
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Hi Eric,

On 11/9/21 11:26 PM, Eric Auger wrote:
> On 8/15/21 2:13 AM, Gavin Shan wrote:
>> The inline functions used to get the SMCCC parameters have same
>> layout. It means these functions can be presented by a template,
>> to make the code simplified. Besides, this adds more similar inline
>> functions like smccc_get_arg{4,5,6,7,8}() to visit more SMCCC arguments,
>> which are needed by SDEI virtualization support.
>>
>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>> ---
>>   include/kvm/arm_hypercalls.h | 34 +++++++++++++++-------------------
>>   1 file changed, 15 insertions(+), 19 deletions(-)
>>
>> diff --git a/include/kvm/arm_hypercalls.h b/include/kvm/arm_hypercalls.h
>> index 0e2509d27910..ebecb6c68254 100644
>> --- a/include/kvm/arm_hypercalls.h
>> +++ b/include/kvm/arm_hypercalls.h
>> @@ -6,27 +6,21 @@
>>   
>>   #include <asm/kvm_emulate.h>
>>   
>> -int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
>> -
>> -static inline u32 smccc_get_function(struct kvm_vcpu *vcpu)
>> -{
>> -	return vcpu_get_reg(vcpu, 0);
>> +#define SMCCC_DECLARE_GET_FUNC(type, name, reg)			\
>> +static inline type smccc_get_##name(struct kvm_vcpu *vcpu)	\
>> +{								\
>> +	return vcpu_get_reg(vcpu, reg);				\
>>   }
>>   
>> -static inline unsigned long smccc_get_arg1(struct kvm_vcpu *vcpu)
>> -{
>> -	return vcpu_get_reg(vcpu, 1);
>> -}
>> -
>> -static inline unsigned long smccc_get_arg2(struct kvm_vcpu *vcpu)
>> -{
>> -	return vcpu_get_reg(vcpu, 2);
>> -}
>> -
>> -static inline unsigned long smccc_get_arg3(struct kvm_vcpu *vcpu)
>> -{
>> -	return vcpu_get_reg(vcpu, 3);
>> -}
>> +SMCCC_DECLARE_GET_FUNC(u32,           function, 0)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg1,     1)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg2,     2)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg3,     3)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg4,     4)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg5,     5)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg6,     6)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg7,     7)
>> +SMCCC_DECLARE_GET_FUNC(unsigned long, arg8,     8)
> I think I would keep smccc_get_function() and add macros to get the
> 64-bit args. SMCCC_DECLARE_GET_FUNC is an odd macro name for a function
> fetching an arg. I would suggest:
> 

I agree. The code will be changed accordingly in next respin.

>> +#define SMCCC_DECLARE_GET_ARG(reg)			\
>> +static inline unsigned long smccc_get_arg##reg(struct kvm_vcpu *vcpu)	\
>> +{								\
>> +	return vcpu_get_reg(vcpu, reg);				\
>>   }
>>   
>>   static inline void smccc_set_retval(struct kvm_vcpu *vcpu,
>>   				    unsigned long a0,
>> @@ -40,4 +34,6 @@ static inline void smccc_set_retval(struct kvm_vcpu *vcpu,
>>   	vcpu_set_reg(vcpu, 3, a3);
>>   }
>>   
>> +int kvm_hvc_call_handler(struct kvm_vcpu *vcpu);
>> +
> spurious change?

I thought the inline function would come before the exposed ones. However,
I don't think it's necessary. I will drop the changes in next respin.

>>   #endif
>>

Thanks,
Gavin