Messages in this thread Patch in this message | | | Subject | Re: [PATCH v10 24/26] KVM: s390: device attrs to enable/disable AP interpretation | From | Tony Krowiak <> | Date | Mon, 24 Sep 2018 14:42:48 -0400 |
| |
On 09/24/2018 12:25 PM, Tony Krowiak wrote: > On 09/24/2018 07:23 AM, David Hildenbrand wrote:
(...)
>> Will you also fixup this patch to expose KVM_S390_VM_CRYPTO_ENABLE_APIE >> only if supported by HW? (ap_instructions_available) > > Given that this patch DOES expose KVM_S390_VM_CRYPTO_ENABLE_APIE only if > supported by HW, I assume you are talking about > KVM_S390_VM_CRYPTO_DISABLE_APIE. I didn't check > ap_instructions_available() for disabling APIE because I didn't > think it necessary given that ECA.28 will be set to 0 (intercept) by > default, whether AP instructions are installed or not; so why not allow > disabling apie. I suppose from the perspective of consistency, since the > kvm_s390_vm_has_attr() function checks ap_instructions_available() for > both attributes, then it probably makes sense to add that check to > KVM_S390_VM_CRYPTO_DISABLE_APIE here. Then again, we could make a change > in ap_instructions_available() to allow KVM_S390_VM_CRYPTO_DISABLE_APIE > regardless of whether AP instructions are available. It boils down to > whether APIE needs to be dynamically disabled at some point when it has > been enabled. The only case I can think of where that may be necessary > is if a guest is migrated to a system without AP instructions. I don't > think that can happen and may even be protected against precisely > because the VM attributes won't be available on the target system due to > no AP instructions. What say you? > David,
I'm sorry, I misinterpreted what you were asking for. Check out the fixup! patch below and let me know if that is what you are looking for. If so, I will integrate that change and post v11 tomorrow (Tuesday 9/24).
-----------------------------------8<-----------------------------------
From: Tony Krowiak <akrowiak@linux.ibm.com> Date: Mon, 24 Sep 2018 14:18:37 -0400 Subject: [FIXUP v10] fixup! KVM: s390: device attrs to enable/disable AP interpretation
--- arch/s390/kvm/kvm-s390.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c index 6654bb1fc26a..a528558baa78 100644 --- a/arch/s390/kvm/kvm-s390.c +++ b/arch/s390/kvm/kvm-s390.c @@ -901,6 +901,10 @@ static int kvm_s390_vm_set_crypto(struct kvm *kvm, struct kvm_device_attr *attr) kvm->arch.crypto.apie = 1; break; case KVM_S390_VM_CRYPTO_DISABLE_APIE: + if (!ap_instructions_available()) { + mutex_unlock(&kvm->lock); + return -EOPNOTSUPP; + } kvm->arch.crypto.apie = 0; break; default: @@ -1509,9 +1513,11 @@ static int kvm_s390_vm_has_attr(struct kvm *kvm, struct kvm_device_attr *attr) case KVM_S390_VM_CRYPTO_ENABLE_DEA_KW: case KVM_S390_VM_CRYPTO_DISABLE_AES_KW: case KVM_S390_VM_CRYPTO_DISABLE_DEA_KW: + ret = 0; + break; case KVM_S390_VM_CRYPTO_ENABLE_APIE: case KVM_S390_VM_CRYPTO_DISABLE_APIE: - ret = 0; + ret = ap_instructions_available(); break; default: ret = -ENXIO; @@ -2620,6 +2626,7 @@ static void kvm_s390_vcpu_crypto_setup(struct kvm_vcpu *vcpu)
vcpu->arch.sie_block->crycbd = vcpu->kvm->arch.crypto.crycbd; vcpu->arch.sie_block->ecb3 &= ~(ECB3_AES | ECB3_DEA); + vcpu->kvm->arch.crypto.apie &= ~ECA_APIE;
if (vcpu->kvm->arch.crypto.apie) vcpu->arch.sie_block->eca |= ECA_APIE; -- 2.19.0.221.g150f307 >> >
| |