Reply-To: Gavin Shan <gshan@redhat.com>
Subject: Re: [PATCH v4 03/21] KVM: arm64: Support SDEI_VERSION hypercall
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>
 <20210815001352.81927-4-gshan@redhat.com>
 <3160dd62-1d96-7dcb-e99a-7ac923abc2c7@redhat.com>
From:   Gavin Shan <gshan@redhat.com>
Message-ID: <be1955d3-4a67-9219-64fa-3dfd46a9eee0@redhat.com>
Date:   Tue, 11 Jan 2022 17:25:13 +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:
>> This supports SDEI_VERSION hypercall by returning v1.0.0 simply
> s/This supports/Add Support. I think this is the prefered way to start
> the commit msg. Here and elsewhere.

Ok.

>> when the functionality is supported on the VM and vCPU.
> Can you explain when the functionality isn't supported on either. From
> the infra patch I have the impression that an allocation failure is the
> sole cause of lack of support?

Yes, it's the only reason that SDEI isn't supported. I will
mention this in the commit log in next respin.

>>
>> Signed-off-by: Gavin Shan <gshan@redhat.com>
>> ---
>>   arch/arm64/kvm/sdei.c | 18 ++++++++++++++++++
>>   1 file changed, 18 insertions(+)
>>
>> diff --git a/arch/arm64/kvm/sdei.c b/arch/arm64/kvm/sdei.c
>> index ab330b74a965..aa9485f076a9 100644
>> --- a/arch/arm64/kvm/sdei.c
>> +++ b/arch/arm64/kvm/sdei.c
>> @@ -70,6 +70,22 @@ static void kvm_sdei_remove_vcpu_events(struct kvm_vcpu *vcpu)
>>   	}
>>   }
>>   
>> +static unsigned long kvm_sdei_hypercall_version(struct kvm_vcpu *vcpu)
>> +{
>> +	struct kvm *kvm = vcpu->kvm;
>> +	struct kvm_sdei_kvm *ksdei = kvm->arch.sdei;
>> +	struct kvm_sdei_vcpu *vsdei = vcpu->arch.sdei;
>> +	unsigned long ret = SDEI_NOT_SUPPORTED;
> nit: I would remove ret local variable

Ok.

>> +
>> +	if (!(ksdei && vsdei))
>> +		return ret;
>> +
>> +	/* v1.0.0 */
>> +	ret = (1UL << SDEI_VERSION_MAJOR_SHIFT);
>> +
>> +	return ret;
>> +}
>> +
>>   int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
>>   {
>>   	u32 func = smccc_get_function(vcpu);
>> @@ -78,6 +94,8 @@ int kvm_sdei_hypercall(struct kvm_vcpu *vcpu)
>>   
>>   	switch (func) {
>>   	case SDEI_1_0_FN_SDEI_VERSION:
>> +		ret = kvm_sdei_hypercall_version(vcpu);
>> +		break;
>>   	case SDEI_1_0_FN_SDEI_EVENT_REGISTER:
>>   	case SDEI_1_0_FN_SDEI_EVENT_ENABLE:
>>   	case SDEI_1_0_FN_SDEI_EVENT_DISABLE:
>>

Thanks,
Gavin