Re: [PATCH v4 06/21] KVM: arm64: Support SDEI_EVENT_CONTEXT hypercall

Gavin Shan
2022-01-13T07:02:44Z

Hi Shannon,

On 1/11/22 5:43 PM, Shannon Zhao wrote:
> On 2021/8/15 8:13, Gavin Shan wrote:
>> +static unsigned long kvm_sdei_hypercall_context(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;
>> +    struct kvm_sdei_vcpu_regs *regs;
>> +    unsigned long index = smccc_get_arg1(vcpu);
>> +    unsigned long ret = SDEI_SUCCESS;
>> +
>> +    /* Sanity check */
>> +    if (!(ksdei && vsdei)) {
>> +        ret = SDEI_NOT_SUPPORTED;
>> +        goto out;
>> +    }
> Maybe we could move these common sanity check codes to kvm_sdei_hypercall to save some lines.
>

Not all hypercalls need this check. For example, COMPLETE/COMPLETE_RESUME/CONTEXT don't
have SDEI event number as the argument. If we really want move this check into function
kvm_sdei_hypercall(), we would have code like below. Too much duplicated snippets will
be seen. I don't think it's better than what we have if I fully understand your comments.

switch (...) {
case REGISTER:
if (!(ksdei && vsdei)) {
ret = SDEI_NOT_SUPPORTED;
break;
}

ret = kvm_sdei_hypercall_register(vcpu);
break;
case UNREGISTER:
if (!(ksdei && vsdei)) {
ret = SDEI_NOT_SUPPORTED;
break;
}

ret = kvm_sdei_hypercall_unregister(vcpu);
break;
case CONTEXT:
ret = kvm_sdei_hypercall_context(vcpu);
break;
:
}

Thanks,
Gavin