Re: [PATCH v10 11/26] s390: vfio-ap: implement mediated device open callback

From: David Hildenbrand
Date: Mon Sep 24 2018 - 04:40:29 EST



> /**
> - * Verify that the AP instructions are available on the guest. This is
> indicated
> - * via the KVM_S390_VM_CPU_FEAT_AP CPU model feature.
> + * Verify that the AP instructions are being interpreted by firmware
> for the
> + * guest. This is indicated by the kvm->arch.crypto.apie flag.
> */
> static int kvm_ap_validate_crypto_setup(struct kvm *kvm)
> {
> - if (test_bit_inv(KVM_S390_VM_CPU_FEAT_AP, kvm->arch.cpu_feat))
> + if (kvm->arch.crypto.apie)
> return 0;

I wonder if this check makes sense, because apie can be toggled during
runtime. I guess it would be sufficient to check if the ap control block
is available and apie is supported by the HW.


--

Thanks,

David / dhildenb